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By D Suppel, Y Miezitis, S Jaireth

The competition between various options for the use of land is ever increasing. Commonly in Australia large tracts of land were un-encumbered by sweeping land use option limitations, but this situation has been rapidly altering in recent decades as governments are obliged to maximise the utility of the land for a broad range of competing interests. While the interests of miners have always been considered, the effects on limiting access to land for exploration and possible mining have not always been effectively incorporated into decision-making processes. As a result the challenge for national and state organisations representing these interests has been to develop a transparent process to allow for the mineral potential of an area to be systematically assessed and for information to be presented for use by specialists and non-specialists. Government agencies are called upon to implement government policy but also to provide accurate and meaningful advice which can assist in policy and land use decisions. Commonly timeframes are short and information can be less than complete. Nevertheless on-going decisions are made based upon the best available understanding. It is in this operational framework that the methods described in this paper are set. The paper describes a process for quickly and systematically providing advice on mineral potential for use by government agencies and ultimately the community within tight time and resource constraints. It is a method of combining the accumulated knowledge about mineral resources and their potential and presenting this information in an easily accessible form which can be used in a negotiation and policy development environment. Development of the method was undertaken to meet the needs of the Regional Forestry Agreement process in Australia. The method has been applied to study areas in New South Wales, Tasmania, Western Australia and elsewhere. Examples in this paper are taken from north eastern New South Wales.

Jan 1, 1999

By S Grimsey, E Janetzki, J Emery

Floor failure on the longwall face is a complex problem due to the dynamic interaction between the surrounding strata and powered roof supports involving multiple variables. It can also be highly problematic and costly when not well understood as there are significantly less remedies available post event. This was the early experience at the case study mine where significant lost time was incurred due to unplanned delays in the first two panels. To detect and prevent such occurrences is clearly the best approach, hence a tool to predict both floor failure occurrence and magnitude prior to mining was developed. Several parameters were determined as the key drivers for the failure events that had been experienced at this site. These parameters were, in list of influence from highest to lowest, material strength, retreat rate and the presence of water. The parameters were evaluated using a semi quantitative risk rating system ‘Heave Risk’ and given a weighting per their apparent influence. This ‘expert system’ methodology was selected as the use of risk rating systems in underground coal mining is well established. The heave risk model was first applied to previously mined panels. It accurately identified all areas of known major floor heave, with clearly defined areas of low and high risk apparent. The heave risk model was then used prior to mining and evaluated post mining based on observed conditions. It was found to also be highly accurate for prediction. The variability of each parameter and its influence on the overall risk rating is illustrated and discussed.

Nov 29, 2022

By G Balog, T Ormerod, D Cox

This paper discusses the methods utilised by the technical team to identify and quantify the SLC risk factors, the modifications to mine design and scheduling, and the changes to the planned risk management practices. The paper also describes the future work currently planned by the OZ Minerals technical team to quantify the various risk factors in terms of space, time and magnitude. This may better inform the future mining practices within not only the Carrapateena province but also the wider Gawler Craton.

Mar 15, 2021

By Rashkovski GB

Until recently amalgamation has been the main process forextracting large gold particles from gravity concentrates obtainedduring the dressing of ores and placer gold deposits.Development of new technology for treating the gravityconcentrates was necessary because of the harmful effect ofmercury on subsequent production processes and theenvironment. The harmful effect of mercury is particularlyevident in the resin-in-pulp process that is widely applied inRussia.

Jan 1, 1993

By J Aitchison, G Clarke

A reappraisal of the stratigraphy, new regional kinematic analysis and thermobarometric data allow a new interpretation of the metamorphic zoning and tectonic structure of the Upper Eocene high-pressure metamorphic core complex of northernNew Caledonia allow a three steps evolution to be proposed: 1. subduction and understacking of previously thinned continental crust elements; 2. subduction blocking due to the crustal thickening; and 3. crustal thinning and extensional detachment during the diapir-like uplift and unroofing of the eclogitic core. Steps 2 and 3 may be partly contemporaneous. Such a model accounts for the thermobarometric and radiochronologic data, and also for the weakness of substratum deformation during the emplacement of the ophiolitic nappe

Jan 1, 1995

By X Xia2, X Wang, G Liang, T Song, F Ma

Inertia cone crushers have found applications mostly in steel slag crushing operations in China. Compared with conventional eccentric cone crushers, the crusher has an obvious advantage in reducing product size. In addition, they are mostly used in two-stage open circuit crushing flow sheet, which simplifies the crushing process. However, inertia cone crushers are not widely used in the mineral processing industry due to their low crushing capacity. In this paper, the throughput performance of the inertia cone crusher was investigated in a laboratory-scale inertia cone crusher and relationships between operational parameters were identified. Iron ore was crushed using orthogonal experimental method under different machine parameters and operational conditions. The crusher throughput and product size distributions were determined. The effects of parameters such as eccentric speed, discharge gap, eccentric mass and eccentric distance on product mass flow and product size were investigated. The results of this study can help reduce the feed size of the mill in order to reduce total energy consumption of comminution.

Aug 24, 2022

By S Garnes, W Austerberry, S Fraser

Despite significant investment in safety in the mining industry (mostly focused on processes and systems), many companies are unable to sustain and further improve their performance resulting in continued workplace incidents. The problem persists despite the best efforts of companies and allocation of resources to achieve Zero Harm. A DSS survey in 2019 found that two out of five companies that cannot manage risks and face disaster, leave the market within five years. All safety/risk management systems have the common steps of risk identification, prioritisation, design of controls consistent with risk tolerance, and verification of implementation/operability of controls. This is then complimented with improvement to one or more of the above elements through learnings obtained from incident investigations. In principle, the above process should work to reduce risks to, and keeping them at, a risk level consistent with risk tolerance in the organisation.

May 5, 2022

All too often engineers and project teams focus on building æthingsÆ, and they tend to see the key goals as meeting the project cost and schedule targets. We frequently compound the problem by unknowingly rewarding engineers for building bigger, more complex, more æbullet proofÆ and hence more costly æthingsÆ. Unfortunately the end result all too often ends up being a disappointment in terms of business performance. The term æshareholder valueÆ may never have entered the discussions during the development process. This paper deals with the fundamental issues, which tend to pre-dispose new developments to success or to failure. As project management concepts are not particularly complex, it begs the question why is it that the failure rate of new developments is so high? It is argued that the answer lies more in people behaviour issues than in project management tools and processes.

Jan 1, 2002

The Mt Muro gold and silver deposit in Central Kalimantan has been in production since December 1994. The geology is characterised by narrow high-grade lodes containing gold and significant amounts of silver. From a largely untrained workforce in the grade control department, production per crew and per geologist has tripled during the three years of production. Grade control drilling evolved from blast hole sampling to reverse circulation sampling. National geologists are trained in basic modeling procedures. A fully integrated reporting and reconciliation system was programed and implemented.

Jan 1, 1997

By R Jaine, D Strang, M Fowler

"This paper presents a case study demonstrating active geotechnical pit slope management at the now completed Carina Iron Ore Project operated by Mineral Resources Ltd (MRL). The site is located 105 km north-east of Southern Cross, Western Australia. The paper is primarily focused on the slope stability failure modes and the remedial measures employed to maintain mining.Between a quarter and a third of the excavated slopes were impacted by some form of instability that was beyond expectations of the intended slope design criteria and common practice. Ongoing mining was supported by intensive geotechnical pit slope management including close cooperation between geotechnical, mine planning and operations staff to achieve timely and practical mining solutions.Mining encountered varied slope failure mechanisms which required a combination of remedial solutions comprising: horizontal depressurisation holes, deferral of excavation, unloading, buttressing and catch berms.The root cause of the challenging slope performance was a mismatch between the predicted and encountered geotechnical model, resulting from a failure to recognise the critical mechanisms that control slope stability.Despite the extensive zones of instabilities at completion of mining, full ore recovery was achieved without major delays and in a controlled and safe manner.Citation:Fowler, M, Strang, D and Jaine, R, 2016. Adapting to Geotechnical Change - a Case Study of the Carina Open Pit Mine, in Proceedings Ninth AusIMM Open Pit Operators' Conference 2016, pp 150–161 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 15, 2016

By E P. Nelson, R Gutierrez, P W. Layer

The San JosT district in Patagonia comprises a number of epithermal precious metal quartz veins hosted by a Mesozoic volcanic sequence. New radiometric data indicates that upper Jurassic volcanism was closely followed by vein mineralisation in the lower Cretaceous. A structural model is discussed for the district at times of mineralization that may also apply on a regional scale and other mineralised districts in Patagonia. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By Longtin Z, Jin C, Zixin C

This paper proposes a new idea of disintegrating mode (division into simpler sub-problems) for complex problems, and based on -it, a study of the structure and the design of a knowledge base and inference engine for layout design of mineral concentrator expert systems. There is also a study of the formalisation method for describing the layout picture, and the work derived therefore found a formalisation method for expressing the knowledge and experience of layout design. There is also a study of the general characteristics of layout design knowledge.

Jan 1, 1993

Underground mechanized excavation in New Zealand has become more commonplace in civil and mining applications during the last three years. At one stage up to seven Dosco Road- header machines were being used on different projects around the country. The Huntly West Mine Drifts inclined at one in four were by far the most severe grade conditions that the machines were subjected to; however, other operations posed their own particular problems for the machines. Two major interrelated factors became evident as soon as the machines commenced at Huntly. These were traction problems on the grade and control of water, particularly on the invert.

Jan 1, 1978

By Bartrop S. B

Mount Isa mine has a long history of successful exploration since discovery 70 years ago. Remaining reserves, although substantial, exist in a scheduling framework which involves long-term production from new ore sources with attendant technical risk and major capital investment. Current exploration aims to incrementally increase reserve tonnage to maintain existing production levels as well as to provide a buffer for potential start-up delays from new ore sources. Exploration also aims to increase the net present value of the operation by discovering new major orebodies around the Mount Isa and Hilton mines.

Jan 1, 1993

By L M. Lobato, J C. S Seoane, F J. Baars

The Carajßs Province presents several volcano-sedimentary sequences that comprise the Itacai·nas Supergroup. The rocks represent bimodal volcanism, and clastic and chemical sedimentation in relatively unstable basins subject to recurrent structural events with subsidence and volcanism. The Grpo Parß Group represents one of these sequences with mafic volcanic rocks that enclose discontinuous jaspilite lenses, with development of large high-grade orebodies (Fe >65 per cent). This unit is named the Carajßs Formation and presents peculiar characteristics compared to other iron districts in the world, thereby departing from the classic Lake Superior or Algoma iron formation types. Owing to the dense vegetation, lack of outcrops and harsh landscape, the structural analysis of the district can only be accomplished by combination of regional field work, detailed structural work on the open pits, and remotely sensed image interpretation, in this case Landsat ETM7, JERS-1 images and the SRTM digital terrane model. The regional trend of the several sequences of the area is approximately N-S and the structure is dominated by a flattened flexural fold system with axes moderately dipping WNW, intersected by several strike-slip faults subparallel to their axial plane. The Serra dos Carajßs represents an s-shaped synform-antiform pair, herein named the Carajßs Fold. This regional structure is partially disrupted by the Carajßs Shear Zone that divides it in the northern (Serra Norte) and the southern (Serra Sul) Ranges and also probably prepared the terrane with the development of pathways for mineralising hydrothermal fluids forming large high-grade massive iron bodies. Syntectonic granitic bodies played an important role in the structural evolution of the area as well. They caused localised ductile flattening deformation and thermal contact metamorphism in surrounding terranes. The Estrela pluton, for instance, was responsible for the discontinuity of the regional trend between the Serras do Rabo and Leste. The Carajßs Province is regionally the upper crustal product of a very shallowly eroded dome-and-keel geometry of Neo-Archaean volcano- sedimentary units intruded by syntectonic calc-alkaline intrusives and overlying pre-existing infracrustal rocks. The lithostructural data suggest continental-margin back-arc basin development and closure in an oblique collision belt, with N-S shallow crustal shortening, parallel to the inferred pre-existing strike of the stratigraphy.

Jan 1, 2005

By B K. Hebblewhite, G Sharrock

The strength and deformation properties of a rock mass are important parameters influencing the design of civil and mining excavations or structures. The mechanical behaviour of jointed rock masses are controlled by the characteristics of discontinuities and the strength of intact rock bridges between discontinuities. To date, analytical, empirical and experimental methods have not captured the key mechanisms controlling the mechanical properties of actual rock masses with non-persistent joints. The emergence of the synthetic rock mass (SRM) in 2007 provides a promising approach for this purpose. In this paper a rock mass with non-persistent joints is analysed with the SRM model based on PFC3D. The influence of joint geometrical parameters on the uniaxial compressive strength (UCS), rock mass deformation modulus (Em) and failure mode is studied. Joint parameters include joint orientation, persistency, spacing and step angle. Prismatic numerical samples with dimensions 300 mm × 150 mm × 50 mm were generated and a sensitivity analysis of each joint parameter on UCS and Em was undertaken. The results show that of the parameters tested, joint orientation has the greatest influence on UCS. Minimum UCS occurs when the angle between the major principal stress and joint surface is approximately 60°. The joint step angle was found to have a significant effect on failure mode and a joint step angle of 90° is the most favourable joint orientation for step-path failure. The importance of joint step angle is highlighted in the discovery of a failure mode bifurcation point at joint step angles of 60° and 90° for joint orientations of 75° and 90°, respectively. For these parameters the failure mode transitions from block rotation to a new failure mode where the coalescence of cracks results in the formation of new small regularised blocks.

Sep 26, 2011

By J Pan

In this paper, the technology of producing fluxed pellets by using hydrated lime as binder instead of bentonite was carried out. The properties of the two types green balls (0.8 per cent bentonite and 2.0 per cent hydrated lime) were as follows: drop numbers of 4.8 - 5.0 times/0.5 m, compressive strength of 19.7 - 24.2 N/pellet and thermal shock temperature of 280° - 385°, respectively, under the same conditions of 1.5 per cent coke, 1.45 basicity and balling at 8.5 per cent moisture for 13 min in disc pelletiser. Comparing with bentonite as binder, the compressive strength of fired pellets with hydrated lime is elevated by 13.8 per cent and climbs up to 3113 N/pellet under the following conditions: preheating at 1050°C for ten minutes and fi ring at 1300°C for 15 min. In the mean time, the hydrated lime also improves the metallurgical performance of fired pellets. The reduction index was enhanced from 68.6 - 70.6 per cent, RDI+3.15+ increased from 90.1 to 98.8 per cent and reduction swelling index dropped from 22.4 - 7.4 per cent, respectively. The mineral compositions and microstructure of fi red pellets shows that the fired pellets containing 2.0 per cent possess more calcium ferrite and magnesium ferrite and compact microstructure, leading to the higher compressive strength.

Jul 11, 2011

New Zealand Steel Limited is nearing completion of the environmental reporting and planning procedures for its proposed fivefold expansion to steelmaking at Glenbrook, and supporting mining operations at Waikato North Head. A report on the proposal to transport concentrate from the mining operations to Glenbrook has also been prepared and is awaiting release. This paper draws from these events, and by discussing some of the problems encountered, gives some guidelines for the preparation of an Environmental Impact Report.

Jan 1, 1981

The concentrating plant of the Broken Hill South Limited was described in Proceedings No. 44, Australasian Institute Mining and Metallurgy, December, 1921, by Wainwright and Read. It was erected on the present site in 1907 and 1908.From that date, the plant has undergone various alterations consistent with metallurgical improvements. By 1925, the timber work of the gravity secti"on had seriously deteriorated, so much so, that, when the machinery was working, the floors and supports vibrated badly, causing heavy maintenance costs.In 1928, it was decided to erect a new gravity-treatment section, to be followed later by a new flotation section.

Jan 1, 1932

By K Baker, J Purtill

One of the key challenges for the mining industry globally is the rehabilitation of mine waste, and Queensland is no exception. Out of pit waste structures including waste rock dumps and tailings storage facilities, create novel landforms which require ongoing maintenance and pose risks to the environment and sometimes to communities. Where multiple mines co-exist, such as parts of Queensland’s Bowen Basin, individual mines can often be constrained by adjoining operations. This presents opportunities for broader rehabilitation strategies to be considered, more than the current single mine focus, that may provide better environmental outcomes for a region. Given recent global disasters involving tailings storage facilities, and our team’s endeavours to drive Queensland to achieve leading practice in mined land rehabilitation, we are exploring the potential to maximise in-pit tailings disposal opportunities for coalmines through shared waste management strategies. A shared waste management strategy is where two (or more) mines, owned by different companies and operated under different environmental permits, transport tailings from one mine to the other in close proximity, for disposal in a disused pit. This would reduce the number of waste structures to be built, operated, rehabilitated, and managed in perpetuity. Our objectives are to identify and remove barriers to tailings transfers between sites to:  minimise environmental risk  minimise long-term liability of managing mining waste and associated structures  support improved outcomes for the local community. To determine the scale of coal waste disposal practices in Queensland, internal data and publicly available imagery was analysed by the Department of Environment and Science in 2022. Approximately 6500 ha of land in Queensland is utilised for coalmine tailings storage facilities or codisposal areas, with ≈ 3700 ha of this being out of pit.

Aug 2, 2023