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By Corbett GJ

The Bulolo Graben represents an intra-arc rift formed by activa- tion of transfer structures in an extensional setting formed be- tween the eastern and western sectors of the New Guinea Origin. Crustal thinning has facilitated the emplacement of dacitic Edie porphyry intrusions, locally as flow dome complexes, phreatomagmatic (diatreme) breccias and the Bulolo ignimbrite/ agglomerate as an extrusive equivalent of the Edie Porphyry. Gold mineralization is localized along intra-graben structures, com- monly at the intersection with cross structures and occurs in sub- sidiary dilational fractures and not the localizing major structures. Gradations are apparent in the styles of mineralization according to the degree of erosion of the hydrothermal system. Hamata occurs as the deepest mineralization of the quartz-sul- phide style Wau, Hidden Valley, and Edie Creek are dominated by carbonate-base metal styles. Kerimenge grades from quartz sulphide through carbonate-base metal to epithermal mineraliza- tion, the latter style also being present in the periphery of Edie Creek. Here, pre-existing fractures of the Edie Creek Structural Corridor have been reactivated by movement on NS structures to form the ore-hosting dilatant lodes. Fluid flow may have been from the vicinity of the Nauti diatreme margin and along the vein System.

Jan 1, 1997

By R Goddard

An alternative stoping method has been adopted for narrow vein stoping at the Tasmania Mine in Northern Tasmania. Colloquially described as ‘Radial-in-Reef’ (RiR) stoping, the method employs the drilling of radial rings in the plane of the Reef from a drill stub located at the geographic centre of the proposed stope panel.Production from the Western Zone of the Tasmania Reef has been undertaken remotely from the Reef since 2007, after a detailed geotechnical engineering analysis indicated that the integrity of the sill drives could not guarantee an acceptable level of confidence should an anticipated seismic event occur within a radius of 10 m. The key tenet of the remote mining approach was the exclusion of personnel from sill drives once stoping had commenced. The remote mining method had to be ‘retrofitted’ to four existing stoping blocks totalling 11 sill drives which totalled 160 m vertically. The remote mining method proved to be complex, cumbersome and very expensive. However, the ore was extracted successfully.By early 2010, previously developed ore had largely been exhausted and the future development with an orebody open at depth presented the opportunity to review the current extraction method. However, the new extraction method needed to maintain the tenet of excluding personnel from sill drives of active stoping blocks, but seek opportunities to reduce the difficult and costly aspects of the previous method. The new ‘Radial-in-Reef’ stoping reduced the development requirement from six to two drives per ore block. Cost implications aside, the significant reduction in prestoping extraction ratio was expected to also reduce the likelihood of seismicity. Transverse production rings were designed to be drilled radially from a drill stub mined from a mid-stope footwall drive. Stopes totalling up to 7000 tonnes were planned be fired in a single electronic blast. Extraction was designed to take place from a basal sill drive under teleremote operation. At the time of writing, the method was under trial.

Mar 21, 2011

By R Young

Independent Project Analysis (IPA) is in the business of benchmarking the performance of capital projects on behalf of owner companies in the processing and extractive industries. IPA assesses between 500 and 800 projects each year. The projects are conducted globally and range in size from about $1 million to over $30 billion. Using the data, we are able to benchmark the performance of Australian projects against the rest of the world. This presentation focuses on the performance of large (greater than $100 million) projects that involve chemical or thermal processing.We regularly hear calls for more processing to be conducted in Australia but on the other hand industry leaders are concerned about the poor success rate of solids processing projects in Australia. Data gathered by IPA indicates that there is good reason for the concern. Out of a sample of 31 large processing projects conducted in Australia, 23, or 74 percent, were classed as failures. This performance is significantly worse than for similar projects in other parts of the world. The presentation analyses why the performance is worse and demonstrates that many of the reasons behind the failures were manageable by the project team. Furthermore, members of the project teams on at least half the failed projects knew that the projects were on a path to failure before the project was authorised but could not be heard.The presentation discusses how large projects that involve process design and, in many cases, new technology, need to be set up for success. *This is an abstract only. No paper was prepared for this abstract.*

Aug 8, 2011

By O Ignatenko, A van Schaik

Environmental legislation for the process and manufacturing industries is frequently formulated without considering the fundamental limits of physics, chemistry and thermodynamics within process technology. Recycling of end-of-life goods is used in this paper to show how the limits can be evaluated on the basis of the theory of minerals processing and metallurgical engineering. This theory has been applied on European Union level to re-examine the legislation for automobile recycling in a recent stakeholder discussion involving the automotive industry (http://www.assurre.org). This theory and our models are finding their way into the computer aided design (CAD) tools of the automotive industry, developments that form part of a project to design the super light car of the future (http://www.superlightcar.com). Only such fundamental approaches will in future be able to provide the basis to argue and define realistic and sensible environmental legislation.

Jan 1, 2006

By K W. Bian, Y M. Liu

Tongkuangyu Copper Mine is currently the only mine in China employing block caving. It comprises two large orebodies known as the No 4 orebody and the No 5 orebody. They are approximately 50° in dip angle, 80 to 240 m in width and 800–1000 m in strike length. The two orebodies are separated by a distance of 110–130 m. Production with block caving originally, ie Phase 1 project started at Tongkuangyu from the first undercut at a depth of 200–300 m below the ground surface and designated as Lift 810 m in late 1989 and has continued to the present. During the last 25 years Tongkuangyu has mined three lifts: Lifts 810 m, 690 m and 530 m. The previous two lifts utilised a slusher process with an annual designed production rate of 4 Mt. In this context the lift name represents the elevation of track haul level.The Tongkuangyu Phase 2 project serves for two lifts (ie Lift 530 m and 410 m) under the elevation of 690 m and the annual designed production rate is 6 Mt. Since the orebody is approximately 50° in dip angle, it is originally designed that production at Lift 530 m is comprised of one main extraction level and two auxiliary extraction levels in the footwall and undercutting is started from one end of the extraction footprint forward to another end, which is from north-east to south-west.Production at Lift 530 m started from March 2011 and reached to 6.39 Mt in 2013 and 6.9 Mt in 2014. Additionally, Tongkuangyu improved block caving processes and used modern mining equipment, which differ from the previous two lifts. Blastholes for undercutting and drawbell-preparation are now drilled using jumbos. The blasted ore is transferred to the underground crushing station via 10 t electric load-haul-dumps (LHDs) and then delivered to surface via a belt conveyor 3200 m long.Due to increasing ground pressure, a consequence of mining depth increase, stress abutment and inadequate support, significant damage occurred at the Tongkuangyu Copper Mine with production at Lift 530 m. This resulted in significant production delays and rehabilitation costs. A series of improvements have since been implemented including an advanced undercut sequence and increased ground support. All of these improvements have allowed Tongkuangyu to alleviate ground control issues, reduce operating costs and ensure safe production.CITATION:Liu, Y M and Bian, K W, 2016. Production at Lift 530 m of Tongkuangyu Copper Mine, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 385–392 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

The past decade hap seen revolutionary advances in com-munications and information-handling techniques which have been stiriulated by "cold war" military requirements and by, current programmes for probing into outer space: The tools used in exploration for petroleum and minerals have been improved significantly as a result of this new space age technology and even greater improvements are on the way.Two areas of technical activity have been particularly fruitful in enhancing the effectiveness of exploration, methods. These are (1) The development of new approaches, based on information theory, for extracting signal from noise more efficiently than before, and (2) The use of high-speed digital computers for storing and processing all kinds of exploration information, not only geophysical but geological as well.In seismic prospecting, use of information theory has led to new techniques such as time-domain filtering, wave-number filtering and correlation methods which have made it possible to obtain usable reflection data from areas which were previously considered NR. Complex playback and other data processing facilities have been developed to apply these approaches.

Jan 1, 1963

By K Jupp, T J. Howard

Cliffs Natural Resources Pty Ltd (CNR) operates iron ore mines in the Koolyanobbing region of Western Australia, about 50 km north of the town of Southern Cross. Ore is trucked from three geographically isolated sources to the crusher at Koolyanobbing, where it is blended before and during crushing. Lump and fines products are produced and railed to Esperance for ship loading and export to Asian customers. CNR is examining alternative processing paths, from mining to ship loading, with the aim of improving efficiency and reducing costs. Modifications to the system must be consistent with potential future expansions and maintain the low inter-shipment grade variability on which CNR prides itself and has built a strong relationship with its customers. In searching for the optimum process design, many options from mine face to ship loading must be evaluated and compared. Pilot plant studies are infeasible, while complex mineralogical interactions, competing goals and numerous possible system configurations limit the applicability of theoretical analysis. It was therefore concluded that simulation modeling would provide the confidence to take the next step into production trials. This paper describes techniques applied at CNR to simulate grade variability resulting from potential process design changes. The simulation models are easily run Excel-based modules, with each module representing a different part of the process. The modules use extensive Visual Basic macros driven by Excel's user-friendly interfaces. Presentation of the results is enhanced by Excel's excellent graphical capabilities. The simulation software stores and graphically presents time-stamped data from a run, enabling detailed analysis of different process configurations. Final success of a simulation run is measured by inter-shipment variability (standard deviation and process capability) and in-process ore tonnages. Meaningful results from the simulations require the initial input data contain the same correlations present in the real production environment, between the mineral components, production linkages and across time. The data also have to allow simulation of potential changes to mining method and introduction of new pits into the blend. Mining data from the real operations under study are therefore used, with average grades and variability adjusted to match potential future development proposals. It is also necessary to filter out medium and long-term variations from the production data as this variability is best controlled through the conventional medium to long-term mine planning process, not by the process design being studied. The filtering was carried out using a Fourier transform technique, which is described.

Jan 1, 2009

By A McCallum, J Abols, G Patrick, G Johansen

The authors challenge the traditional thinking that whole ore cyanidation followed by Carbon in Pulp (CIP) or Carbon in Leach (CIL) should be applied as a standard process in the majority of gold processing flow sheets. The concept of whole ore leaching by using cyanide can result in unnecessary environmental and capital risk. Alternative, currently available technologies can be used to provide the desired level of gold recovery at a much lower installed cost and less impact on the environment. Gravity concentration, alone or in conjunction with flotation, can produce a gold bearing concentrate that can then be fed directly to a batch or continuous intensive cyanidation unit. The In-line Leach Reactor (ILR) is an intensive cyanidation unit developed by Gekko Systems of Australia. Advantages of this technology include significantly reduced capital outlays for greenfield plants or plant upgrades and increased investor returns. Reduction of onsite cyanide and carbon inventories improves plant safety, materials handling and site security. By using direct electrowinning to treat the gold bearing solutions produced by the ILR, the need for a conventional carbon stripping circuit is removed. Potential also exists to increase grind size û saving energy, further reducing capital and operating costs and decreasing the environmental impact of a mill. Detoxification of cyanide before the release of solution to the tailings dam can minimise tailings disposal and containment requirements. When used in the right application the proposed process will have little or no impact on gold recovery and may actually increase recovery for complex ores. Areas applicable to this type of treatment include: plants in environmentally sensitive regions, lower tonnage higher grade deposits, coarse gold deposits, and preg robbing ores û some of which may not currently be economically feasible using standard processes and flow sheets. We have provided two examples of such projects, where an alternative to whole ore leach and CIP or CIL has the potential to deliver these benefits.

Jan 1, 2004

By W Kendall

Ore sorting has the potential to reduce the feed to wet plants and in the case of complex orebodies that can significantly reduce the water, energy and reagent consumptions and resulting operating costs for the project. The application of ore sorters has sparked renewed interest and application in the precious and base metals mining industry in recent years as a result of the continuing development of new sensing technology and very fast information processing that is making ore sorters applicable to a much wider range of ores and larger scale operations. The application of ore sorters involves a range of trade-off decisions that have economic impact upon the benefits of ores sorting to the project under consideration. This paper will present some typical trade offs to be considered and their impact in a particular project setting. CITATION: Kendall, W, 2018. How economics drive the application of ore sorting, in Proceedings Complex Orebodies Conference 2018, pp 24–27 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

As the title indicates the central themes discussed in this contribution are sustainable development, information systems, and extractive industry. More specifically, the objective is to present a prototype for the systematic generation of extractive industry (henceforth: EI) û specific sustainability information. The paper begins with the authorÆs viewpoints on the core notions of sustainability, and development, as well as their relationship to information. These set the stage for the introduction of the information system (IS), as well as the follow-up sustainability information system (SIS) extractive industry sustainability information system (EISIS) concepts and related discussions. The paper continues with a second part, in which, efforts to research and develop an EISIS prototype are described. First, the team is presented. Second, the systemÆs aim and target groups are briefly discussed. After, an articulated overarching EISIS conceptual model emphasising capital accumulation, and service flow concepts û is presented. This is followed by a detailed description of the assembled prototype with a focus on data and information generation. The formulation of data generation, storage and transmission processes, as well as its use in sustainability interpretation rules and their embedment in the conceptual model is made with respect to monetised stock and flow parameters, measured in the appropriate dimensions. In the third part, the author presents and discusses the results of a first round of prototype experimental development in three major EI firms. First, the system observation, and data analysis protocols are described. Second, a review of protocol implementation, and respective results, is made. Finally, the overall performance of the proposed prototype, and development process issues are discussed, before suggesting areas for improvement and future research. The paper ends with a conclusion in which the author provides a retrospective balance of the æknowledge creation projectÆ, as well as a prospective outlook for research in this field; before acknowledgements are made and references provided.

Jan 1, 2009

By Robinson T

The paper describes a spreadsheet system that enables selection of projects and companies that meet the user's corporate exploration and/or acquisition philosophy. A regularly maintained commercially available database has been used as the basis for this system. It provides an easily accessible efficient com- prehensive search method. The technique enables ranking by various criteria, both technical and financial, to provide groups of projects/companies that are of interest. Initially, target size parameters such as reserves, production and mine life are applied together with geological criteria such as age and deposit type; the significance of the targets in the context of the Australian gold industry is addressed.

Jan 1, 1988

By M K. Singh

Mining is nothing but an art - besides being a science - of extracting valuable minerals from the womb of the mother earth. In this gigantic task, a large number of machinery and equipment are employed judiciously. Wire ropes play a vital role in lifting or hoisting men and materials under hostile/adverse working conditions and constitute a major item of investment on machinery/equipment. The economy of using a wire rope is a concern for engineers, users and the planners. The economic use of wire ropes for mining purposes largely depends on the following factors;Mechanical design considerations - which include tensile strength of wires, elasticity, resistance to abrasion and crushing, fatigue values, static and dynamic loads on wire ropes, factor of safety, fleet angle, etc. Metallurgical consideration - Composition and heat treatment of wire materials, defects like inclusions and voids, surface quality factor, lubrications, micro structural parameters. Operational consideration - Seizing and cutting of rope, storage, care and maintenance, cutting back, etc. Environmental consideration - Temperature and humidity, pit condition, dust, corrosive atmosphere, etc. In the present paper, an attempt will be made to suggest steps for achieving optimum economy while using the wire ropes for extraction of precious minerals and coal keeping in view the points noted earlier. Once technical viability is established, economy is the ultimate consideration for an industry for safe hoisting of men and material.

Jan 1, 2000

By Massacci P

A review has been made of the studies focusing on methods for the description of grain -size distribution after breakage and, separa- tely, of the degree of liberation of the miner- al species making up the various grain-size classes of comminution products. The purpose of the study has been to de- velop an overall model of the phenomenon which, owing to the very effect of comminution, leads to the formation of grains that are generally of mixed composition. A calculation procedure has thus been de- veloped for the liberation function taken as the assessment of the distribution of mix com- ponents in the products obtained after a commi- nution process. The aim is to identify a func- tion which may, to a certain extent, simulate the variation of the grade-recovery function of an ore in relation to its degree of comminu- tion. The numerical model thus obtained has been tested out on results obtained experimentally.

Jan 1, 1986

By Abishev D. N, Balakirev V. F, Davydov G. I

The problem of recovery of cobalt products from poorly oxidised nickel ores (Kempirsaisk deposit) and pyrite concentrates with a low content of cobalt (Sokolovsk-Sarbaisky deposit) has not been solved to the present time in Kazakstan. The balance reserves of nickel ore of the Kempirsaisky deposit make up more than 35 million tons with a nickel content of 1.13 per cent and cobalt content of 0.05 per cent; besides there are 110 millions tons of out-balance ores (Anon, 1995). In a tailing dump of Sokolovsk-Sarbaisk Mining and Productional Association more than 320 million tons of tailings of wet magnetic separation have accumulated, which contain 7.2 per cent of sulphur, 0.022 per cent of cobalt, 0.012 per cent of nickel, 0.094 per cent of copper, 0.079 per cent of zinc, 16.45 per cent of iron, and from which a high quality pyrite concentrate car) he separated through flotation, containing 48 - 50 per cent of sulphur, 44.15 per cent of iron, 0.141 per cent of cobalt, 0.07 per cent of nickel, and 0.10 per cent of copper. The well-known technological flow charts for cobalt and nickel recovery from the tailings of sulphide-magnetite ores dressing (to give pyrite concentrate) and from oxidised nickel ores, are not profitable at the existing prices for metals, but are not worthless and require significant capital investments for the realisation of their value. The flow chart `sulphate roasting - leaching - solution processing' is used widely for combined processing of cobalt-containing pyrite ores and concentrates.

Jan 1, 1996

By R Verreet

In April 2000 Mount Isa Mines installed hoist ropes of a new design on the double-drum winder at their P49 shaft. The ropes, CASAR Duroplast, were about three times as expensive as the previously used triangular strand ropes. The P49 shaft is situated at Mount Isa MinesÆ George Fisher Mine, located some 30 km north of Mt Isa. This shaft used the tried and proven 6 x 33 triangular strand style ropes. The rope life attained by these ropes at the time was acceptable due to many years of satisfactory performance. The following study indicates the improvement of service life using CASAR Duroplast rope in P 49 shaft, which depends on shaft and winder parameters of that particular shaft and cannot necessarily be generalised to other shafts.

Jan 1, 2005

By J P. Barkas

World demand for iron ore is far from peaking, and the substantial price decline that has captivated commentators since early 2014 is not the result of widespread misreading by producers of the prospects for global market growth. Recent price movements provide little useful insight into the industry’s longer-term fortunes, apart from reminding mining companies that their businesses need to be robust against the volatility and inescapable cyclicality of mineral commodity markets. It is timely to take a strategic view of the history and longer-term prospects for the iron ore industry and of Australia’s place in it.CITATION:Barkas, J P, 2015. Perspectives on the long-term outlook for iron ore, in Proceedings Iron Ore 2015, pp 3–6 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By M J. Nimmo

extremely powerful tools for building predictive and generative models. ML can be used for building highly accurate regression and classification models. But without careful data science and statistical analysis, a regression or classification model could be highly biased and completely wrong – and we may not even realise. An example rock density estimation task will be used to illustrate the potential gains and possible pitfalls in using ML and AI in Mineral Resource estimation. What could possibly go wrong? Nothing! For most simple regression or classification problems, very little. For density estimation, using the global mean may be all that is possible, but the resource classification would need to reflect the uncertainty in global estimation of tonnage. Everything! From data collection and measurement, from selecting ML and AI techniques and designing the analysis workflow to our own cognitive bias. The things that could go wrong are vast and may include but not limited to asking the wrong question, not asking questions, data bias, measurement errors, insufficient data coverage, not collecting the right variables, not collecting enough observations, collecting clustered samples, unbalanced data, filtering out data without reason (outliers), clipping data (outliers), relying on automatic feature selection, including irrelevant variables, excluding relevant variables, geological interpretation, changing context, blindly following best practice, splitting small data sets, subsetting large data sets, using the wrong tool for the task, insufficient budget to complete the analysis, not allowing enough time for testing and experimentation (the science), focusing too much on building the model (the engineering), not learning from the data, our assumptions, our preconceptions, and our skill. This paper will explore the question of how training regression models to predict rock density are affected by gaps in the data (missing observations and missing variables). What could possibly go wrong?

May 24, 2023

By Y Xu, J Hacker, D J. Williams

Shear strength parameters of compacted clay liners are needed to analyse the stability of mine waste dumps containing compacted clay liners as sealing layers for potentially acid forming waste rock. A representative clay sample was supplied by McArthur River Mine from the mine site in the Northern Territory, Australia, with an average as-supplied gravimetric moisture content of about 13.6%. The clay was compacted in a 100 mm by 100 mm direct shear box at the as-supplied moisture content to a dry density of 1.85 t/m3, representing the field compaction specification adopted by the mine. To determine the peak and ultimate shear strengths of the compacted clay, single-stage direct shear testing was carried out at nominal initial normal stresses of 50 kPa, 100 kPa and 200 kPa, representing shallow depths of burial in the North Overburden Emplacement Facility of about 2.8 m, 5.6 m and 11.1 m, respectively (assuming a waste rock wet unit weight of 18 kN/m3). Three shearing rates of 1 mm/min (rapid), 0.1 mm/min (intermediate) and 0.01 mm/min (slow) were applied to study the influence of shearing rate on shear strength. In addition, the development of a residual shear plane was tested by reversal and re-shearing in the direct shear box. In the first shearing, the peak and ultimate shear strengths are determined. The normal load was then removed and the box rewound to its starting position. The normal load was then re-applied and the specimen re-sheared. Two reversals were applied to each specimen, and it was found that there was no significant reduction in shear strength. Finally, based on a range of shear strengths obtained in the laboratory for McArthur River Mine clay and other materials by various laboratories over time, shear strength parameters for the compacted clay were recommended for use by the mine.CITATION:Xu, Y, Williams, D J and Hacker, J, 2018. Shear strength of compacted clay liner at McArthur River Mine, in Proceedings Mine Waste and Tailings Stewardship Conference 2018, pp 208–219 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 23, 2018

By A Querzoli, B Williams

In late 2014 the Flinders Power Management Team was executing business improvement plans to ensure continued electricity generation until 2028 and beyond. Six months later, in June 2015, the Board announced the closure of the Flinders Power South Australian business, including the Leigh Creek Coal Mine, the Northern and Playford Power Stations located at Port Augusta and the 250km railway line. The announcement was preceded by a brief period of internal planning. A date was soon set for ceasing coal mining operations, being November 2015. The mine is unique in many ways. Located approximately 550km north of Adelaide the site has over 100 years of history and was formerly operated by the South Australian Government. Privatisation in 2000 saw the mine continue operation under Perpetual Leases from the South Australian Government. The leases included exemptions from multiple sections of the Mining Act 1971, obliging primary regulation under the Mines and Works Inspection Act 1920. The coal, being a low rank sub-bituminous brown coal, is prone to self-heating and spontaneous combustion. The mine and company town Leigh Creek were the economic and cultural heartbeat of the community. Facilities at the mine were shared by the community and vice versa. While many mines across Australia and the world enter periods of care and maintenance, few have been actively closed to the point of relinquishment (Bennett and Lacy, 2016). A swift decision to close, followed by a short mining operations shutdown period, presented significant technical and regulatory challenges for both the mine operator and for Regulators. The subsequent joint risk mapping process employed by Flinders Power and South Australian Mining Regulators was a unique real-world example of collaborative mine closure planning and execution. Lessons learnt are valuable for all mines, production facilities and for Regulators, even for those who may wrongly assume that closure is many years away. CITATION:Williams, B and Querzoli, A, 2018. Risk management for minesite closure planning and execution – start now! Lessons from the closure of the Leigh Creek Coalfield, South Australia, in Proceedings Life-of-Mine 2018, pp 68–72 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

Development of a global failure criterion for rocks has been a desired goal in rock mechanics. Due to variations in factors affecting rock specifications and their mechanical properties, proposing a single failure criterion suitable for all rock types has proven to be unachievable. The theoretical failure criteria do not fit the real data correctly. Amongst empirical criteria, the Bieniawski criterion has demonstrated an acceptable agreement with laboratory generated data. It has been experienced that the ability to estimate rock strength via the modified form of this criterion is significantly improved. Based on the modified Bieniawski criterion and using VB.net, an associated Microsoft Windows program named 'RAMOCE' has been developed. The inputs of RAMOCE can be triaxial compressive strength data, Bieniawski parameters of a specific rock or the type of given rock. Based on input data, potential outputs of the program are Bieniawski's rock parameters, sensitivity analysis of the effective parameters, rock failure prediction and defining the type of given rock.

Nov 25, 2010