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The pressure of low commodity prices forced the design process for the second lift of Northparkes E26 Mine to adopt a continuous improvement philosophy. The emphasis was to minimise capital expenditure while still maintaining the excellent low operating costs achieved on Lift 1. Although the first block cave lift at Northparkes is the most productive underground mine in the world and is held up as a benchmark for the use of technology in mining, areas for improvement were identified. Every area was critically assessed and investigated for the possible application of new techniques and technologies. Key learnings from the construction and production phases of Lift 1 were captured, documented and used as the starting point for the Lift 2 design. This paper shows how and why the design parameters initially used onLift 1 were changed to become the current E26 Lift 2 developmentproposal. The main differences between the two block caves arehighlighted. The alternative techniques and equipment that wereconsidered are also discussed. * Originally published in the Proceedings of MassMin 2000,published by The AusIMM.

Jan 1, 2001

Igneous phosphate deposits located in tropical and subtropical regions of the world are characterised by low P2O5 grades, very diversified mineralogy and intensive lateral plus vertical variations in chemical composition, mineralogical assembly, rock texture, grain size, slimes content and morphology plus surface coating of apatite particles. Those variations characterise ore types with distinct behaviour in mineral processing plants. This work reviews the main challenges to concentrate those ores, addressing developed solutions. Apatite concentration requires long chain anionic collectors to conduct reverse flotation of barite (alkyl sulfate) before direct flotation of apatite (sarcosinate, sulfosuccinate and oleate) at basic medium. The long chain collectors decrease the surface tension of the flotation solution (?LV) and a particular value of 51 mN/m was found to promote the most selective separation between apatite/gangue at a particular plant. Effective control of the magnitude of ?LV in industrial plants has not been realistic because there is a lack of reliable instruments to carry out in-situ measurements. Regarding gangue depression by starch, a review is made on possible mechanisms that promote its remarkable ability to depress some minerals (Fe-oxides, ortho plus meta silicates and calcite) vis-a-vis others (quartz, apatite and layered silicates). Flotation recovery (R) of fine (20<R<30 per cent) and coarse (30<R<60 per cent) apatite particles is considerably lower than the recovery of the intermediate ones (R>70 per cent) and inadequate hydrodynamic conditions within flotation cells are the main reasons for that behavior. Once the best hydrodynamic conditions to float coarse particles are not the same to float the fine ones, flotation of coarse and fine particles is commonly conducted at separated circuits in industrial scale. Entrainment of very fine gangue particles is an important source of contamination of apatite concentrates, mainly when weathered ores are treated. In most cases, adjustments in flotation equipment (columns or mechanical cells) promote considerable improvement in the quality of final concentrates.

Sep 13, 2010

By A Karrech, C Schrank, O Gaede, I Canbulat

Strain-based failure criteria have several advantages over stress-based failure criteria: they can account for elastic and inelastic strains; they utilise direct, observable effects instead of inferred effects (strain gauges versus stress estimates) and they model complete stress-strain curves, including prepeak, non-linear elasticity and post-peak strain weakening. In this study, a strain-based failure criterion derived from thermodynamic first principles utilising the concepts of continuum damage mechanics is presented. Furthermore, implementation of this failure criterion into a finite element simulation is demonstrated and applied to the stability of underground mining coal pillars.In numerical studies, pillar strength is usually expressed in terms of critical stresses or stress-based failure criteria where scaling with pillar width and height is common. Previous publications have employed the finite element method for pillar stability analysis using stress-based failure criterion, such as Mohr-Coulomb and Hoek-Brown, or stress-based scalar damage models.A novel constitutive material model, which takes into consideration anisotropy as well as elastic strain and damage as state variables, has been developed and is presented in this paper. The damage threshold and its evolution are strain-controlled, and coupling of the state variables is achieved through the damage-induced degradation of the elasticity tensor. This material model is implemented into the finite element software Abaqus and can be applied to 3D problems.Initial results show that this new material model is capable of describing the non-linear behaviour of geomaterials commonly observed before peak strength is reached as well as post-peak strain softening. Furthermore, it is demonstrated that the model can account for directional dependency of failure behaviour (ie anisotropy) and has the potential to be expanded to environmental controls such as temperature or moisture.CITATION:Gaede, O, Schrank, C, Canbulat, I and Karrech, A, 2014. A strain-based failure criterion for pillar stability analysis, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 393–398 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By A R. Sale

This paper highlights two aspects of the mineral sands industry in Australia: the development of the industry from approximately 1870 through to 1980, and the author’s experience in the industry from 1966 to date.The first real heavy mineral (HM) mining in Australia started in 1870 with the mining of heavy mineral slicks on the beaches along the east coast of Australia. The real potential of Australian heavy minerals was however only realised in the 1920s with the first production of a heavy mineral concentrate that was shipped to Canada for processing. Post WW 11 and the Korean War, Australia was the largest producer of mineral sands products in the world as well as a significant developer of associated separation equipment and technology. The number of producing companies in the east coast peaked at 33 in 1957, was reduced to ten by 1965, and subsequently further reduced to five in 1980 as a result of potential mining areas being declared National Parks or Conservation Reserves. Today there is one company, Unimin Australia Pty Ltd (formally Consolidated Rutile Ltd) operating on the east coast. In contrast there were three companies on the west coast in 1965, four companies in 1980, and four companies today (albeit not the same companies).There have been considerable ups and downs for the industry in Australia, however world wide it was renowned in the past as being an industry that attracted numerous interesting and innovative characters that played a major role in developing it into the vibrant industry that it is today. This, given the current climate, is predicted to continue into the future.The author has been continuously involved in the industry for over 45 years from 1966, initially as an electrician at Consolidated Rutile Ltd culminating in the role of General Manager/President of Iluka Resources Limited USA, prior to his retirement in 2009. His exposure has been world wide and has covered all aspects of the industry but in the main focused on project development and operational areas. During this time there have been significant technological advances, yet to some extent the basic principles have not changed at all. Some of the most noteworthy advances include the development of the Wright Spiral in 1977, the development of the Reading High Intensity Wet Magnet (WHIMS), the rare earth magnets, the CRL floating thickener and the improvement of analytical techniques. From a safety, health and environmental perspective there has been significant advances that the industry has much to be proud of. These include wetland restoration both in Australia and in the US, the restoration of farmland in Virginia and Capel, and the re-establishment of native species, for example at Eneabba and Richards Bay to name but a few.

Oct 5, 2011

The Mineralogical Researches of Gold Ores and Technological Products at Operating Factory in Olympiada Mine (Russia)

Sep 13, 2010

Successful evaluation and exploitation of resources and reserves relies on the collection of high quality sample data. The quality of the sample data must be maintained through the application of a robust quality assurance and quality control (QAQC) program, including documentation of sampling procedures, training of sampling personnel and the regular monitoring of control samples. However, the application of QAQC programs in the minerals industry is often poor and the purpose misunderstood. It is all too common to have good quality control data collected, but no analysis work carried out until after drilling is completed. In a lengthy drill program, this can lead to problems not being discovered and corrected as they happen. Moreover, rectifying problems afterwards will be costly in terms of time and money, if not impossible. The consequences of poor quality sample data are many and include such effects as over- or underestimation of block grades, misclassification of ore and waste, and lower confidence in the resource/reserve models. The purpose of this paper is to highlight, using case studies, the importance of good QAQC practices to monitor the quality of sampling and laboratory sample preparation and analysis.

Mar 1, 2010

Mine rehabilitation is a sustainability issue that has been revisited ad infinitum; however, the persistent lack of demonstrated on-the-ground performance and an increasingly intractable rehabilitation liability in Queensland continue to erode the credibility of the mining industry and regulatory bodies. For at least ten years the need to change the current, process-based approach to rehabilitation to an outcomes-based approach has been apparent. The ISO 14001 series temporarily diverted attention from this important point, however it would appear the limitations of an ISO 14001 approach are now more widely accepted. It is proposed that a successful outcomes-based approach cannot be achieved without meaningful community engagement. The apparently intractable nature of the rehabilitation issue will continue to generate conflict and criticism unless all stakeholders are encouraged to participate in the process of developing robust and practical outcomes for rehabilitation. Sharing the responsibility will ensure the best possible outcome. It is important to recognise the valuable resources inherent in community groups, many of whose committed volunteers have considerable expertise in relevant areas. Community groups should not be seen as adversaries but as allies in the process of solving problems that affect the wider community. Several projects that can be seen as test cases for the engagement of stakeholders exist, and in this paper the process of achieving multiple stakeholder engagement in the context of Environmentally Sustainable Development is discussed.

Jan 1, 2002

By D N. B Skinner, R L. Brathwaite, M S. Rattenbury

The Institute of Geological and Nuclear Sciences is undertaking a mineral resource assessment study of the Coromandel region, due for completion in July 2000. A key part of the study is the assembly of a geographic information system (GIS), a computerised tool for layering, analysing and presenting spatial information. The GIS is being assembled with ArcInfo/ArcView software and to date includes layers for a digital terrain model, an aeromagnetic map (open file mining company data), a geological map (from the QMAP project), areas of hydrothermal alteration, locations of mineral deposits (GERM database), stream sediment geochemical analyses (REGCHEM database), and a lineament map derived from satellite remote sensing data.

Jan 1, 1999

By Z Terzic, M Schult, D Chu, S Macklin

The East West Link road tunnels are proposed to provide a connection between the CityLink toll road and the Eastern Freeway north of the Melbourne CBD. The alignment passes from Moonee Ponds valley beneath the Upfield Line railway cutting, Royal Park, the historic Melbourne Cemetery and beneath Alexander Parade rising to an eastern portal at Hoddle Street. The western (Royal Park) part of the alignment passes through the folded and faulted Silurian Melbourne Formation, which has been subjected to deep weathering since the Triassic.The Melbourne Formation in the Royal Park area is mainly characterised by interbedded sequences of siltstone and fine-grained sandstone. The beds are often graded and a clear boundary between the siltstone and fine-grained sandstone rock can be difficult to distinguish. Variation in lithology and the presence of structural geological features such as folds and faults have resulted in an irregular weathering profile within the Silurian rock; nonetheless the formation typically becomes less weathered with depth.Due to difficulties in obtaining reliable laboratory strength and stiffness relationships with weathering grade, in situ testing methods such as downhole shear wave velocity and high-quality pressuremeter testing are a useful aid to assessing appropriate geotechnical parameters for design.This paper presents an analysis of the variation in shear modulus of the Melbourne Formation, determined at small-strain (from downhole seismic data) and at ‘engineering scale’ strain (from pressuremeter tests) for extremely weathered (XW), highly weathered (HW) and moderately weathered (MW) rock. Estimates of small strain shear modulus (Go) obtained a range between 400 to 3400 MPa for these weathering grades. By comparison against the pressuremeter test data, reduction factors to be applied to these Go values to estimate shear moduli at engineering strain levels typically range between 0.10 and 0.35.The downhole geophysics undertaken in the Royal Park boreholes also suggests that there is an inversion in velocity between approximately 15 and 27?m depth below the top of the formation. This is thought to be related to the effects deep Plio-Pleistocene weathering, iron cementation of joints and increasing frequency of ‘non-healed’ joints in the transition from MW to slightly weathered (SW) rock.CITATION:Macklin, S, Schult, M, Terzic, Z and Chu, D, 2014. Strain-dependent stiffness of the weathered Melbourne Formation, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 179–188 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By M Burdick, A Harding, M Krulc, M Chappell

Substantial schedule advantages can be made on projects if cross-passage construction can occur at the same time as tunnel boring machine (TBM) operation with little or no impact on TBM logistics. However, this approach can prove difficult to achieve with many of the more cost-effective means of supporting the segmental lining during cross-passage break-out. This paper discusses the constraints and shortcomings of conventional approaches, and describes how a cost-effective solution involving a shotcrete shell and opening constructed inside the segmental lining was designed and constructed to deliver cost and time savings on Seattle University Link contract U220.The paper explains the spatial and schedule constraints on the TBM tunnelling and cross-passage construction, and how a shotcrete solution was arrived at in preference to traditional approaches. As the solution was novel the design had to be robust, and the paper explains how this was achieved through a combination of 3D finite element modelling and closed form solutions. Following a description of the trials to verify that the structure could be demolished post-cross-passage completion, the paper describes how the shell solution was constructed, used and demolished safely to leave the lining surface in a clean and undamaged state fit for tunnel operation.CITATION:Harding, A, Chappell, M, Burdick, M and Krulc, M, 2014. Opening supports to segmental linings – a novel shotcrete support solution, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 267–274 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By T Raynlyn, S Hapugoda, V Nunna

The predominant phase in most Marra Mamba, channel iron deposits and detrital iron ore deposits is goethite. Goethite abundant iron ore fines tend to have complex mineralogical associations and fine dissemination of gangue material. These ores are typically challenging to process using conventional beneficiation methods. With declining ore grades, there is a need to develop new processing routes for low-grade goethitic ores/fines.Comparative process amenability studies were carried out using two different processing options to recover iron with low alumina and silica content from a low-grade goethite-abundant iron ore fines (-2 mm) sample from the Pilbara region of Western Australia. The first option involved dehydroxylation at 350°C and 400°C, followed by grinding dehydroxylated samples to 100 per cent passing 106 µm and magnetic separation. The second option was processing raw sample by gravity separation using a Floatex density separator. The performances of the two processes are discussed in terms of the iron grade-recovery responses, and an optimal processing route is proposed based on the findings from these tests.CITATION:Nunna, V, Hapugoda, S and Raynlyn, T, 2015. Process amenability studies on goethite-abundant iron ore fines, in Proceedings Iron Ore 2015, pp 165–174 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

Roles of Mineral Impurities and Sulfur in the Leaching Behaviour of Pre-Reduced Ilmenite Ores

Sep 13, 2010

Efficiency, Economics, Energy and Emissions - Emerging Criteria for Comminution Circuit Decision Making

Sep 13, 2010

By J Zhang, B Wei, T Zhao, K Wang

Understanding mining-induced surface movement and fissures is critical for environmental protection and geological prevention. In this study, image recognition algorithms, satellite remote sensing and unmanned aerial vehicle photogrammetry (UAVP) were combined to identify surface movement and fissures caused by mining, and a case study was conducted in a coalmine in western China, and the following conclusions were obtained.

Sep 1, 2024

By M Doran

The Olympic Dam mine utilises 1.1 m to 1.4 m diameter raise bores for generating the initial slot void for most production stopes. Slot raise bores generally span two development levels ranging from 30 m to 50 m in height. Raise bores are reamed upward and typically leave a cap of rock equivalent to two times the raise bore diameter on the drill level (minimum 3 m). This provides safe access over the cap for subsequent production activities. It is therefore critical to ensure robust falling object protection for personnel accessing underneath, and in the vicinity of the raise bore void on the lower level. Recently, a number of mesh failures have occurred at Olympic Dam as a result of falling rock from the underside of the cap and raise walls. In addition, as Olympic Dam transitions to deeper and more challenging ground conditions, rockfall-off onto the raise bore protection mesh is anticipated to increase in frequency. This paper discusses the evolution of raise bore protection mesh used at Olympic Dam and presents results from recent site-based drop testing. This impact testing was carried out using a built for purpose object to replicate point loading and shear failure of mesh wires. Testing was also carried out on an improved mesh design which utilises two layers of Geobrugg high-tensile MINAX mesh. Results from the drop testing suggest an improvement in performance of the raise bore protection mesh is realised with the updated design.

Mar 29, 2023

By S Jokanovic

At New Zealand Steel MiningÆs Waikato North Head operation a Bucket Wheel Excavator û shiftable conveyor mining system is used to excavate titanomagnetite bearing sand and clay. The system utilises two Bucket Wheel Excavators and two Beltwagons with a two shiftable bench conveyors and two common trunk conveyors to deliver material to a processing plant. The original system was commissioned in 1984 as a high capacity, low cost method of excavating. In 1996 a second Beltwagon was purchased, increasing the flexibility of the mining system.

Jan 1, 2002

Avoca Resources LimitedÆs Higginsville Gold Project has a resource base of over 1 300 000 oz of gold. The Trident underground mine, which forms the basis of the project development, has a resource base of 927 000 oz of gold. Avoca is building the Higginsville Gold Project based on a minimum ten year vision, producing over 150 000 oz per annum. The project development has taken less than three years from the Trident discovery hole in October 2004 to the first ore production in June 2007. This paper discusses the background work associated with the development of the Trident underground mine in a difficult period for new project development in Western Australia. The resources boom, led by the iron ore industry in the Western Australian Pilbara region, is creating cost pressures and, combined with a lack of people and equipment, is placing cost and timing stress on a small developing project. Avoca Resources has developed a project execution management strategy aimed at mitigating cost blow outs and schedule delays.

Jan 1, 2008

The long-term outlook Tor Australla's traditional mining products is for flat demand and continuing low prices. This has come about because of three far-reaching changes since earlier boom days: 1. Continuing declines in intensity of usage of basic mine products; 2. The failure of newer western and third world developing countries to realise growth expectations; and 3. Continued production pressure from third world countries (and first-world primary producers) in an effort to earn foreign exchange and rectify trade balances. These trends have led to a general situation of excess supply and weak demand. In this environment, the prerequisites for survival in the mining sector are first-class mines, modern and efficient production methods, low unit costs, aggressive marketing, and products with reasonable operating margins. Many of Australia's mines meet these prerequisites. Following the A$ depreciation and widespread unit cost reductions, most of these mines will be moderately profitable at current depressed commodity prices. They are well placed to benefit from price rises if these eventuate. A new generation of mines is concentrating on a more profitable product range (gold, diamonds, uranium, mineral sands). Australia's balance of trade remains firmly dependent on the primary mining and agricultural industries (Fig. 1). Despite optimistic talk of high-tech developments, tourism and a resurgence of manufacturing, these will remain a small component of Australia's export structure.

Jan 1, 1987

By Dean J. A, Taube A, White A. H, Messenger P. R, Jones I. W O, Huston D. L

The 50 million tonne Mount Morgan gold-copper deposit (4.99 g/t Au, 0.72 per cent Cu) was an irregular pipe-like body of quartz and pyrite, with subordinate chalcopyrite, magnetite and gold. Mineralisation was hosted by the Middle Devonian Mine Corridor Volcanics which occur as a roof pendant within the Late Devonian Mount Morgan Tonalite. On three sides, the deposit was enclosed by a series of normal, concave, listric faults and surrounded by outward-dipping Mine Corridor Volcanics. The tonalite which bounded the western side of the deposit transgresses the domal structure with no apparent interference. A pipe of intense, texturally-destructive, quartz-sericite-chlorite ¦ pyrite underlay and partly surrounded the deposit.The volcanic setting of the deposit, its shape, metal content and associated footwall alteration are consistent with a subsea-floor replacement origin for the gold-copper mineralisation. Mineralogical studies have confirmed the deposit has been recrystallised and annealed by a thermal metamorphic event, most likely the intrusion of the Mount Morgan Tonalite. Pyrrhotite Pipe mineralisation replaces annealed massive pyrite, suggesting that it formed during retrogressive metasomatism associated with tonalite emplacement. Telluride minerals have a close association with chalcopyrite, and no evidence for a late telluride paragenetic stage was observed. Telluride mineralisation is inferred to be genetically related to the massive sulphide mineralisation, and a separate magmatogenic origin for this mineralisation is discounted.

Jan 1, 1993

Modelling and Optimisation of Direct Reduction of Iron Ore by Coal in a Rotary Kiln

Sep 13, 2010