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By J Channell, G Phillips

"The Chesney deposit, located 4 km south-east of Cobar consists of three copper-gold rich shoots that lie within a larger, copper dominant lode. A fourth gold rich shoot is located adjacent to the main deposit. The deposit exhibits a strong structural control on mineralisation, as brittle deformation during subvertical extension provided the requisite structural traps to precipitate sulfides from solution. It is postulated that the Great Chesney Fault acted as a fluid conduit, conveying fluids to the site of orebody formation. The continual supply of fluids resulted in cyclic brittle deformation when the fluid pressure exceeded the lithostatic pressure and the tensile strength of the Great Cobar Slate.Evidence supports the hypothesis that ore deposit formation was controlled by: a supply of mineralised fluids transported along the Great Chesney Faulta suitable location for the mineralised fluids to accumulate, accommodated by vertical extension and dilation in certain locationsthe creation of suitable structural traps to capture the sulfides. These traps formed as a result of fault-valve behaviour. Understanding the controls on mineralisation enables prediction of the location of other deposits with similar emplacement history, or extensions of current deposits.CITATION:Channell, J and Phillips, G, 2014. Understanding mineralisation controls – a case study of the Chesney deposit, in Proceedings Ninth International Mining Geology Conference 2014 , pp 301–312 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 18, 2014

The reasons for and the methods of inte- gration of the gold treatment plant with the existing nickel concentrator are discussed. The integration was accomplished in three stages commencing in May 1980 and attain- ing current throughput in December 1982. The problems encountered and their solution, including the design and construction of a new tailings dam are also discussed.

Jan 1, 1984

By A R. Bonani, M P. Pe±a

The optimisation of slope angles, that is to say, increasing them, compared to the original design is always the subject of analysis of stability for geotechnical engineers and economic analysis for planning engineers. Questions to be answered include: What is the acceptable risk? What factor of safety? What probability of failure or reliability? The Rosario Open Pit has a history of failure, poor quality rocks and high pore pressures. It was decided to deepen the pit below the programmed design to test the practicality of different design approaches, which if successful, could be used to improve the economics of mining at Collahuasi. The revised slope design has factors of safety in the range of 1.0 to 1.2, probabilities of failure of ten to 38 per cent, and increased slope angles of between 3¦ and 5¦ with respect to the original design. The pit deepening with these design slopes will deliver an extra two million tonnes of ore which will have a significant positive impact on mining economics.

Jan 1, 2007

By J Dwyer, G Turner, D Pridmore, M Urosevic

Due to their ability to produce high-resolution images of the subsurface to great depths, seismic surveys provide critical inputs to almost all oil and gas exploration projects. However, with some notable exceptions, seismic surveys have rarely been used in mineral exploration. In the past, this was due to both technical and financial reasons. Significant developments on both fronts mean that seismic surveys can now offer substantial benefits to mineral exploration and mining, and surveys conducted for exploration can provide important data sets for mine planning over the life of a mining project.We present case history data that show that seismic surveys can greatly assist with mapping the 3D distribution of lithologies and alteration and, in favourable circumstances, directly detect mineralisation in and around mineral systems. As a result of their high spatial sampling density, seismic surveys are also highly effective at mapping structures that can remain undetected or poorly characterised by drilling alone. These structures may host or provide important vectors to mineralisation. They can also be particularly important when planning shafts, raise bores, declines, stopes and open pit walls. A further benefit of seismic surveys is that they can remotely provide information on geotechnical rock parameters that are used for rippability, slope stability, blasting and ground support.CITATION:Turner, G, Urosevic, M, Pridmore, D and Dwyer, J, 2015. Exploration and mining unified through seismic imaging, in Proceedings Third International Future Mining Conference, pp 117–122 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

By Yanske TR, Lane WL

The Doc Run Company and its predecessors have been mining for over 130 years utilising the room and pillar mining method. This method has left approximately 20 per cent of the orebody in the remaining pillars. The original design and planning for the mines did not include extensive pillar extraction. This paper summarises the introduction of the pillar extraction and backfill techniques which have been implemented since 1991. These techniques include the use of low cost fill walls up to 20 in in height and the use of stinger trucks for topping off the fill. In conjunction with these accomplishments, much experience and confidence has been gained in the use of numerical modelling as a method of predicting pillar stability as the mining of pillars progresses. These advances have led to pillar extraction hecoming a major portion of the overall production and have added to the mine life of Doe Run's six operating mines.

Jan 1, 1998

By Dixon CA

In the early 1970s, Jim Walter Resources, Inc. (JWR) embarked on a coal mine expansion program that was unparalleled in the history of the United States. With a small nucleus of people then operating two rapidly depleting captive mines, action was initiated to develop four of the deepest mines in the United States. Because of the depth of these mines, operational and technical problems were anticipated. However, because of the high quality of the coal (Blue Creek Seam), the financial risks involved were acceptable. The total investment to get the expansion program completed (to get the new mines to full capacity) would represent an investment of over US$ 500 million.By the end of the decade of the 1970s, the Company had grown to 2100 employees who were producing 1640,000 tonne of saleable coal per year, a productivity rate of 3.9 tonne per man-shift. This productivity rate was not sufficient to maintain a profitable, viable organisation. Therefore, if the operations were going to survive, it would be necessary to improve productivity tremendously, a task which would tax the resources and imagination of all employees.

Jan 1, 1991

This paper covers only the energy uses of natural resources and does not deal with non- energy uses, which in 1975 were of the order of 10 per cent of the total consumption of energy resources. The United Nations `J' Series of Statistics ex- presses each of the various forms of energy in terms of its coal equivalent in metric tonnes and this basis is followed in this paper. One tonne of black coal (referred to as tce) has been taken as the equivalent of the following. 29 X 109 joules or 27.5 X 106 Btu 0.68 tonnes or 4.8 barrels of crude oil 750 cubic metres or 26.5 X 103 cubic feet of natural gas 1 ò5 to 3.3 tonnes of peat or lignite (world average 2.54; Victorian brown coal 3 0) 8055 kWh (at 3.6 X 106 joules or 3412 Btu per kWh at 100% efficiency) 2660 kWh at 33% efficiency of generation 50 grams of uranium present in natural uranium reactors (see note later under nuclear energy) 0.8 grams natural uranium in breeder reactors Nuclear and hydro electricity are expressed as the coal equivalent required to produce, at 33 per cent efficiency, the same amount of electricity. In other words, electricity produced by these sources is converted to its coal equivalent at the rate of 2660 kWh = 1 tonne coal.

Jan 1, 1978

By N Petropoulos and M J Thurley, E Righetti, M Wimmer

Fragmentation in sublevel caving (SLC) is vitally important. Both gravity flow and any downstream processes are affected. Reasonably coarse fragmentation may lead to larger draw bodies (isolated extraction zones) and hence potentially higher primary ore recovery and depressed/delayed waste rock inflow from above. Fewer flow disturbances are expected by mitigating oversize. In addition, it requires less boulder handling and reduces wear and possible hang-up problems in orepasses. To assess the present-day functionality of large-scale SLC, a multiyear, comprehensive measurement program was initiated. It covers the main elements for SLC, namely blast function, fragmentation and gravity flow. The present paper focuses on fragmentation measurements. An image acquisition system was used to document the drawpoint and the load-haul-dump (LHD) bucket for each mucking cycle. At the beginning, four buckets (about 70 t total) were sieved to validate the results of both 2D and 3D image analysis techniques. The fundamental and specific problems are discussed herein. At the moment, fragmentation of the SLC rings is evaluated using a quick rating system and a 2D fragment delineation software. The results enable a description of fragmentation and its variation during mucking but also – combined with the gravity flow measurements – conclusions on the fragmentation for different parts of the SLC ring. Possible influences on flow disturbances and ore recovery/dilution are investigated. The recent findings allow a better understanding of breakage and flow and support future process improvements.CITATION:Wimmer, M, Nordqvist, A, Righetti, E, Petropoulos, N and Thurley, M J, 2015. Analysis of rock fragmentation and its effect on gravity flow at the Kiruna sublevel caving mine, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 775–792 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By Cocks T

The 15-year long debate between the industry, Government and Aboriginal people about the rights and wrongs of Land Rights, the right of Aboriginal people to control development on their land and the relationship between the parties, has been long and often bitter. It has so far been a war of words and often the truth has been the first casualty. This paper looks at the debate and presents the perspective of Aboriginal people, as well as looking at how the industry and Aboriginal people can work together for everyone's benefit. It addresses such matters as: ò why Aboriginal people believe they have the right to control development on their land; ò the perception that Aboriginal people are anti-development; ò the perception that Aboriginal land is 'locked-up'; and ò how companies can negotiate with Aboriginal people.

Jan 1, 1994

By K Luthbom, A Lagerkvist

According to the Swedish Environmental Protection Agency, the number of potentially contaminated sites in Sweden is approximately 40 000. The funding for remediation from the Swedish Government alone amounts to $A 60 - 80 M (300 - 400 MSEK) annually for the period 2003 - 2006. Uncertainties will arise when obtaining samples in field, preparing them in laboratories and analysing them. Different procedures give rise to varying errors. Using data for decision-making that does not truly represent the site could be fatal. Misclassification of soil could lead to unnecessary costs or to risks to human health and the environment. The total uncertainty of an environmental sample can be split into analytical uncertainty and sampling uncertainty. The analytical uncertainty is usually known and reported from routine analysis. The size of the sampling uncertainty is less well known. Hence, the question is how big are the sampling uncertainties for contaminated soil and how big is the analytical error compared to the total sampling error? A scrap yard and two landfills within a workshop area were investigated. An excavator dug trial pits and samples were taken with a trowel from the walls of the trial pits. Samples were put into plastic bags and taken off site for preparation and analysis using XRF. Sample preparation included drying and sieving. The samples were homogenised by kneading the sample bags prior to analysis. The sampling and sample handling were performed in an intuitively way without knowledge of sampling theory. However, Pierre GyÆs sampling theory was used for subsequent evaluation of the data from the site investigation. The theory defines seven sampling errors, which can be applied to sampling of soil. Some errors have a variance that can be calculated or at least estimated, while other errors can give some idea whether the bias is positive or negative. The total sampling error varied over three orders of magnitudes from sample to sample. The single largest contributor to the large variation in error was the contaminant level. When comparing the analytical error and the total sampling error the ratio varies more than three orders of magnitude.

Jan 1, 2005

By A Hall, D Kratochvil, P Littlejohn

Economic recovery of gold from complex gold ores, including poly-metallic deposits, is impacted by the presence of cyanide-soluble base metals. These base metals can create both a metallurgical challenge plus waste handling and disposal challenges. Base metals such as Cu and Zn compete for the cyanide reagent and often increase the total cyanide consumption to the point of making precious metals recovery uneconomic. In addition, the accumulation of base metals in cyanide solutions represent a challenge for cyanide detoxification and waste water treatment as these metals report to waste sludge. Such sludge requires safe handling and disposal, with possible long-term liabilities.Base metal interference can be removed with sulfidisation-acidification-recycling-thickening (SART) process technology. SART liberates the base metal from the cyanide complex and precipitates the metal as an insoluble sulfide product that can be recovered as a commercial grade concentrate. With the base metal precipitated, the cyanide can be regenerated as free cyanide and recycled to the gold extraction circuit.BioteQ completed laboratory testing for two projects, one employing cyanide leaching of copper-gold sulfide flotation concentrate and one employing a Merrill Crowe process, to determine the effectiveness of SART to remove and recover Cu and Zn in high-grade sulfide concentrates and to reduce the impact of cyanide-soluble metals on gold recovery and cyanide consumption. This paper will provide an overview of the testing methodology and results along with a review of the potential for SART to be applied to complex gold ores with poly-metallic deposits to improve project economics, operability and waste management.CITATION:Littlejohn, P, Kratochvil, D and Hall, A, 2013. Sulfidisation-acidification-recycling-thickening (SART) for complex gold ores, in Proceedings World Gold 2013 , pp 149-156 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By B F. J Kelly

Multiple-point simulation is a family of methods used to generate conditional facies simulations that present the same spatial dependence as a user-defined training image. The main advantage of using a training image is the easy integration of geological concepts in numerical subsurface models. The strength of multiple-point methods is that it allows making the best use of geological expertise when data are too sparse for inferring a model of spatial continuity. However, despite being appealing to geologists, the multiple-point methods are often not used in practice due to the difficulty of building complex 3D training images that contain realistic features.A new framework for multiple-point simulation is presented that involves small and simple training images. The main idea is to use random transformations to expand the range of structures available in the simple training image. The training image is not regarded any more as a global conceptual geological model, but rather a basic structural element of the subsurface. Complex geological structures are obtained, whose spatial structure can be parameterised by adjusting the statistics of the random transformations, based on field data or geological context. In most cases, such parameterisation is possible by adjusting two numbers only. One advantage is that the training images are so simple that they can be easily built even in 3D. The method allows building 3D models that reproduce shapes corresponding to a desired prior geological concept and are in phase with different types of field observations, such as orientation, facies or geophysical measurements. The flexibility of the approach allows for naturally integrating different types of data. This is demonstrated on an example involving seismic data assimilation. Examples where complex 3D folded structures are built from a simple training image and a few orientation data are shown.

Sep 26, 2011

By M Hilden, K Barbosa, M Yahyaei, C Ndimande, K Runge, V Jokovic

Classification devices provide a link between comminution and flotation. Basically, it determines which particles are diverted back for additional grinding and which ones pass to downstream flotation. Therefore, the classifiers play an important role in the performance of a mineral processing circuit. Hydrocyclones are the most common classifiers used in wet grinding, despite being associated with poor classification efficiency. Hydrocyclones are widely used due to advantages related to low maintenance as well as reduced capital and operating cost. Other classifiers, such as fine screens, have much better classification efficiency compared to hydrocyclones. The major challenge of using screens in an operation, however, is their large footprint and increased maintenance requirements relative to hydrocyclones. Some researchers have demonstrated that switching from hydrocyclones to screens, as the classifier device in a ball milling circuit, resulted in a 20 per cent increase in plant throughput and significant improvements in coarse particle recovery, resulting in a 6 per cent increase in overall flotation recovery. However, it is known that these benefits of improved classification are very much ore specific, ie depending on the ore response. Therefore, there is a need to estimate the benefits of improved classification in pilot scale testing before the plant could consider the potential classifier upgrade. This paper presents the results of two pilot-scale grinding tests where the ore sample was processed using different classifiers: a traditional hydrocyclone and hybrid classification involving the use of a semi-inverted hydrocyclone followed by a screen. The size specific energy and circulating load were used to compare the performance of the grinding circuit. The grinding product was subject to mineral liberation analysis and the impact of classification efficiency on the mineral liberation is discussed in the paper.

Aug 24, 2022

By B Patterson, Y Lanwin

Over the last decade the adoption of autonomous technology has proven its potential to fundamentally alter the mining industry, offering significant improvements in safety and productivity. Automation levels are now increasing exponentially across all parts of the supply chain from drilling, haulage, processing, rail and shipping to the maintenance of the above. However, the management of human error risk is also becoming increasingly complex as the disconnect between the people who operate and interact with mining equipment and those that design the autonomous systems grows in terms of skill and expertise. Furthermore, as comfort levels with automation increases amongst operators, complacency is increasing as the initial functional safety benefits have been realised. This paper introduces an innovative concept that unites two distinct fields, functional safety and behavioural economics, to address the complex issue of human error risk in autonomous mining operations. Functional safety, a well-established field in engineering involves identifying potential hazards, assessing risks and designing systems in a way that minimises the chances of accidents and limits their consequences. Meanwhile, behavioural economics takes a data centric approach to analysing the psychological aspects of human decision-making, acknowledging and seeking to understand the errors that can originate from cognitive biases and heuristics. This paper seeks to bridge these domains by emphasising that human error in autonomous mining is not solely a technical issue but is deeply influenced by human behaviour and decision-making processes. By incorporating insights from behavioural economics, we can better predict, prevent and manage human errors in the mining sector. By applying principles from both disciplines to a recent incident example we will explore how cognitive biases can impact peoples’ interactions with autonomous mining equipment. This interdisciplinary approach will not only enhance the design and implementation of functional safety measures in mining but also lead to the development of people centric solutions that consider the inherent fallibility of people. We will explore how human centred design can help bridge the gap between these two domains and apply systems thinking for a universal approach. Through an indepth case study analysis and empirical data, our research aims to provide actionable insights and practical recommendations for mining industry professionals, regulators and stakeholders involved in the safe integration of autonomous systems.

Apr 16, 2024

By P Gleeson, J Coombes, P Suresh, T McLennan

The last 20 years have seen a dramatic rise in the use of 3D visualisation and modelling for geological data, but there has been relatively little effort to do the same for the variogram models that underpin the standard estimation algorithms used by the mining industry.For kriging, one of the most used geostatistical estimation methods, specifying a variogram model is a critical part of the modelling process. Experimental variography is the primary method for approximating the theoretical variogram function from the available sample data, and then determining an appropriate variogram model from the approximations.The traditional tools used for experimental variography are limited to looking at subsets of the data and are often presented without reference to geographic space and geology. It can be difficult to know what input data is being used for a particular experimental variogram, and whether there is enough support in the experimental variograms to propose an appropriate model.To overcome these limitations, an innovative approach called situational variography has been proposed that visualises variograms in 3D alongside contextual geological and geometric data. Presenting variograms in this manner aids understanding of how the spatial variance relates to the underlying data.A 3D extension of the 2D radial variogram maps will be investigated which allows for dynamic exploration of the full experimental variogram cloud. These 3D experimental variograms are much easier to visualise situationally.A workflow for situational variography will be outlined and the advantages of the situational approach will be illustrated using a porphyry copper deposit.CITATION:Gleeson, P, McLennan, T, Suresh, P and Coombes, J, 2017. Situational 3D variography – determining the variogram in the context of geology, in Proceedings Tenth International Mining Geology Conference 2017, pp 191–198 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

Most coal mines in Chongqing Area are highly gassy mines and liable to outburst of coal cnd methane. In order to harness mine environment and raise the Prodction capacity, methane predrainage is generally taken as a main preventive measure against outburst by all mines. In the recent ten years, the drainage volume per year has increased from 38.25 million m3 to mote than 100 million m3 with a volume over 12 m3 per tome of coal. In some mines, the draining rate is approaching to 50 percent, the rate in mining districts is up to 60 to 70 percent. The predrainage volume accounts for one fourth of total drainage volume. All these have effectively prevented the occurrence of coal and methane outbursts.This is the current situation of methane predrainage in coal mines in Chongqing area, the methods of predrainage to prevent outbursts and related parametres comprise:1. methods, technologies, supervision and effect of predrainage in different geological and mining conditions,2. the change of methane parametres pre-and post-drainage and the analysis of the effect of methane predrainage to prevent outbursts, and3. ways to improve the effect of methane predrainage.Thus the safety, reliability and production of Changqing Coal Mines will be enhanced.

Jan 1, 1991

By G Bournival, Y Pan, S Ata

A custom-made set-up that measures bubble coalescence time and the thin film balance (TFB) technique were used to explore the role of residual xanthate (potassium amyl xanthate, PAX) and salt (NaCl) on the adsorption of two frothers (methyl isobutyl carbinol-MIBC, and di-propylene glycolDPG) at the air-water interface. This paper is primarily focused on the comparison of these two techniques in studying the interaction between the flotation reagents and salt emphasizing their capabilities and limits. The results from the coalescence rig showed that the presence of PAX improved the stability of bubbles in both frother solutions and led to a bubble coalescence inhibition at 50–500 ppm DPG. These measures were compared with the results from the TFB. Findings from the TFB were overall in good agreement with the bubble coalescence time, but a higher stability level was observed in thin films under the same condition. The effect of salt on the frother and PAX mixture was also explored, and the results showed an adverse impact of the salt on the interaction of frother and PAX with both techniques. However, variations were found between them in some cases. The TFB is much more sensitive to the presence of dissolved gas and oil droplets.

Aug 24, 2022

By J MacNeil, R Dimitrakopoulos

As open pit mining of a deposit deepens, the cost of extraction may increase up to a threshold where transitioning to mining through underground methods is more profitable. This paper provides an approach to identifying an optimal depth at which a mine should transition from open pit to underground mining. The value of a set of candidate transition depths is investigated by optimising the production schedules for each depth’s unique open pit and underground operations. By considering the sum of the open pit and underground mining portions’ value along with the cost of transitioning corresponding to each candidate transition depth, the optimal transition depth can be identified. The optimisation model presented is based on a stochastic integer program that integrates geological uncertainty. As an input, the stochastic integer program utilises a set of several stochastic simulations that represent equally probable scenarios of the mineral resource. This group of simulations describes the uncertainty in the deposit, while the optimiser aims to maximise value based on discounted profits of both the open pit and underground components of the deposit.CITATION:MacNeil, J and Dimitrakopoulos, R, 2014. A stochastic optimisation formulation for the transition from open pit to underground mining within the context of a mining complex, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014, pp 363–368 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

By A M. Lechner, V Glenn, M Edraki, D R. Mulligan, C Unger

With more than 50 000 recorded abandoned mines in Australia, effective management strategies are needed to prioritise and manage health, safety, environmental and socio-economic risks and opportunities. This paper reviews international leading practices for abandoned mine management and identifies key issues that need to be addressed in the Australian context. As well as the academic literature, this review draws on a 2008 global legacy site survey and forum in 2008, a Churchill Fellowship study of abandoned mines and the recently released æStrategic Framework for Management of Abandoned Mines in the Minerals IndustryÆ (MCMPR/MCA, 2010).A conceptual model was developed to identify the relationship between key issues affecting the management of abandoned mines in Australia. The conceptual model is then used in the development of a maturity chart which draws on risk management principles to provide leading practice guidance for abandoned mine managers, jurisdictions and stakeholders. The maturity chart approach for risk management has been successfully used elsewhere to evaluate safety, environmental and socio-economic maturity.CITATION:Unger, C, Lechner, A M, Glenn, V, Edraki, M and Mulligan, D R, 2012. Mapping and prioritising rehabilitation of abandoned mines in Australia, in Proceedings Life-of-Mine 2012 , pp 259-266 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 10, 2012

By N Anderson

The world-class Golden Mile gold deposit in the Eastern Goldfields of Western Australia is part of the Kalgoorlie Consolidated Gold Mines (KCGM) operation, which is wholly owned by Northern Star Resources Limited. Current mining operations across the Golden Mile is dominated by the large Fimiston Open Pit, which is over 4 km long, 1 km wide and 600 m deep. It is part of a larger mineralised system that stretches over 8 km and includes the Mt Charlotte Underground Mine, which is also operated by KCGM, as well as numerous historical open pit and underground mines. This mineralised system has been continuously mined for over 125 years and is set to continue well into the future. The Golden Mile deposit is in the Norseman Wiluna Greenstone Belt which is made up of a series of mafic volcanic and sedimentary rocks that have been structurally deformed and intruded by granitic rocks. There are two main styles of mineralisation across the Golden Mile. Firstly, the Fimiston style, which consists of shear hosted Golden Mile lodes with abundant sulfides and tellurides and secondly, the Charlotte style that comprises younger stockwork veins. Fimiston style mineralisation is the primary style of mineralisation within the Fimiston Open Pit. Historically, in excess of 3500 m of underground development and over 755 stopes were mined prior to the consolidation of the area and the commencement of Fimiston Open Pit operation. Old underground workings, known as voids, are either empty or backfilled and extend to more than 1.2 km below surface. Although they are a routine part of mining operations at KCGM, voids pose a significant challenge for the geology team in terms of planning and executing exploration and grade control drilling, geological modelling, grade and tonnage estimation, drill and blast design and execution, marking up ore block designs, mining, and reconciliation. This paper will discuss the various challenges faced by the geology team due to the presence of voids, solutions used to overcome some of these challenges and the results of these activities.

Mar 22, 2022