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By A C. Edwards

The Mesozoides of North-Eastern Asia represent a collage of exotic terranes which were accreted to the margins of the Siberian continent. In the Late Precambrian and Phanerozoic, the passive margin of the Siberian continent (the current north-east) broke up into a number of discrete fragments as a result of rifting events in the Riphean, Early and Middle Paleozoic. Rift related mineralisation includes stratiform and stratabound copper and base metal mineralisation in the structures of the Omulevka, Okhotsk and Prikolyma basement terranes, as well as along the edge of the Siberian continent in the Paleozoic sediments of the Verkhoyansk passive margin. During the Late Mesozoic the terranes were reassembled in a series of accretionary events. At the end of the Jurassic, the velocity of the Kula plate increased, and the opening of the Canadian Basin in the Arctic commenced, changing the vectors along which the Siberian and North American plates moved. Island arcs terranes were pushed back onto the Omolon super-terrane which was in turn pushed onto the Siberian Craton in a series of massive collisional events that resulted in the restructuring of the whole region. Numerous granitoids characterised by collisional and island arc chemistries with Au and accompanying Sn, and W mineralisation were emplaced. Mesothermal gold-quartz mineralisation was emplaced in a series of narrow belts that adjoin major crustal sutures and that spatially overlap belts of granitoids and zones of subgreenschist metamorphism. Each of these gold-quartz vein belts corresponds with a specific collisional phase. In the middle Cretaceous, the Okhotsk-Chukotka volcanic belt developed along the paleo-Pacific margin of the Siberian continent. Epithermal Au-Ag developed in the volcanics and shallow mesothermal Au-Ag-quartz and Au-Sb mineralisation developed in the Mesozoides. Porphyry and skarn style mineralisation developed in both the island arcs and in the continental Okhotsk-Chukotka Volcanic Belt.

Jan 1, 1999

By J Deraisme, P Epinoux, O Bertoli

"Société le Nickel exploits the Dôme lateritic nickel orebody at its Tiébaghi operations in New Caledonia. The site geology has an obvious bearing on recovery and metallurgical performance, with controls that are extremely complex at all scales, including lithology, oxydo-reduction conditions, mineralogy and multivariate geochemistry. In this context, establishing an adapted recoverable resource estimation method that is efficient and transparent proves an interesting challenge. The method must address the key notions of: support effect – the exploration data set can only warrant the estimation of large panels of 20 × 20 × 3 m3 that are much larger than the selective mining units (SMUs) of 5 × 5 × 3 m3 information effect – the selection at the production stage uses estimates based on information that is much denser than that available for mine planning.The problem is rendered more complex in this type of deposit by the fact that the additive variables used for the estimation (metal accumulation and ore tonnage) are not the ones used to establish the selection at the mining stage (ie the nickel grade of SMUs, which is the ratio of accumulation on tonnage). Eventually, the selection criteria not only involve Ni grades, but also other elements such as Al2O3, Fe2O3, MgO and SiO2.The solution presented in this paper is to construct an SMU multivariate simulation in the saprolitic horizon and construct an efficient post-processing aimed at producing multivariate recoverable resource estimates. The efficiency constraints imposed by the number of blocks to be simulated (1.5 million) lead to resorting to direct block simulations. The underlying multivariate discrete Gaussian model, which had its validity tested beforehand, is put to good use to mimic the selection process that happens at the mining stage by offering the ability to simulate a composite value located at random within each block.The paper also presents the application of a scenario reduction algorithm to pick a representative subset of a few simulations to help appraise the risk attached to the downstream (reserve optimisation and mine sequencing) phases of the project. The original version of the paper (see Deraisme, Bertoli and Epinoux, 2014) used an early version of the scenario reduction plug-in (named S2RM) built in Isatis® software, where measuring the distance between the initial set of scenarios and the reduced set was based on Ni only. The implementation presented here is for the second generation of S2RM, where measuring the distance between the initial and the reduced set of realisations is based on all study variables. The benefits of the measure adapted to the true multivariate nature of the problem are highlighted in this updated version of the paper.CITATION:Bertoli, O, Deraisme, J and Epinoux, P, 2014. Multivariate block simulations of a lateritic-type nickel deposit and post-processing of a representative subset, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014, pp 99–108 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 24, 2014

By W Patton, I Minniakhmetov, H Talebi, U Mueller

The sustainability of mining projects is linked to informed investment decisions based on public reporting of exploration and mineral resource estimation results. In Australia, public reporting guidelines are established by the Joint Ore Reserves Committee reporting code through the JORC Code (2012). Although the assessment of uncertainty in the results reported is a requirement, this is often communicated qualitatively and evaluated subjectively. This can become a liability particularly in the early stages of mining projects when spatial domains of geological interpretation and mineralisation envelopes inform resource estimations’ reliability. A recent review of JORC reports found no reports used quantitative assessments of the geological interpretation or mineral resource estimation envelopes, and 27 per cent of reports did not address the question of quality of geological interpretation. Reports that did address the quality used 19 different terms to communicate quality. This work presents methodologies for quantitative uncertainty assessment and communication and explores how they could be applied in public reporting practice. Quantitative uncertainty reporting would benefit mine planning and financial modelling as they normally assume the geology is 100 per cent right (since no error is reported or only a single deterministic model is provided). The complexity, cost, and additional work of doing a quantitative assessment could hinder a straightforward implementation. This could be overcome if mining companies budget for quantitative uncertainty assessment and associated professional development. A compulsory requirement for the inclusion of uncertainty assessments in public reporting or adopting standardised subjective language would improve industry practice.

Mar 22, 2022

By T G. Neville, G Terrey, J Burns

This paper explores recent industry training programs and lessons for supervisors. The Belbin Team Role model was used to increase participants’ awareness of behaviour and its application. The application of the Belbin model to underground, open cut mine and quarry supervisors is discussed.The key to team success may rest with the expertise and experience of its members, but increasingly effectiveness depends on how team members understand, acknowledge and support each other’s behavioural strengths. Discovering strengths is a challenge, both for their measurement and for the encouragement of team members to use the knowledge of themselves and others in the team. Using behavioural models provides a constructive approach and a language for supervisors as they build personal motivation and engagement.Prima facie, the mineral industry’s work may be too vigorous for teams and their managers could be more prone to use ‘solo’ or traditional management styles. Managers and supervisors must know when work allocated to a team is appropriate or where individual effort should be applauded and rewarded. For practical people with well-developed technical skills, improving the soft skills necessary for a supervisor requires some reflection and effort. The Belbin behavioural model can be an effective tool for recognising characteristics that can assist teams to be more productive.Experiencing the Belbin Team Role model as part of an industry qualification is important for supervisors studying to refine their team leadership skills. Data are available for participants to assess the nature of their teams and to confront the appropriateness of the behavioural mix for the work of the team and its individual members.So what are the next steps? All team development must have a place in the strategic thinking and plans of the enterprise. This needs a visible presence of senior managers and supervisors in managing a team culture with practical links to workplace priorities and professional development with continuous improvement.CITATION:Burns, J, Terrey, G and Neville, T G, 2016. Supervisors and teams at work, in Proceedings International Mine Management Conference, pp 125-138 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 22, 2016

By Forrester P. I, Richardson W

Methane in coal mines is an ever present hazard resulting in loss of lives and serious economic consequences. For effective control of methane, ventilation alone may not be totally adequate in some situations. In order to deal with such cases, new methods for the control of methane are being researched. One such method based on biotechnology has been investigated in Canada in the past several years. This method involves bringing methane oxidizing micro- organisms into contact with coal to oxidize the methane released to non-flammable products.

Jan 1, 1988

The explosion at Appin Colliery on July 24th, 1979, demonstrated the need for a large scale facility to simulate an underground type explosion and study its effects. The effects of an explosion cannot be established quantitat- ively using small scale models. A gallery was constructed for this purpose at Londonderry Centre and commissioned in Feb- ruary, 1980. It is 50 metres long, 2.7 metres in diameter, capable of withstanding an internal pressure of 210 kPa and is the only facility available for this purpose in Australia. The gallery has provided valuable inform- ation on blast effects of explosions in tunnels and is to be used for testing the performance of explosion arresting devices, further invest- igation of explosion effects, research into basic explosion phenomena and instrumentation development. Additionally, it will provide a demonstration facility for training purposes.

Jan 1, 1981

By E N. Sparg, O D. A Deuchar, F Needham

Decline shafts are an attractive option to both new and existing mining operations where there is a need to access an inclined orebody deposit via on-reef development so as to generate a return in the shortest possible time. There are many different technologies that are available to transport men, material and rock in incline shafts. This paper focuses on the applicability of two hoisting technologies for decline shafts, namely endless and direct rope systems. The pros and cons of each system are reviewed. A common concern with direct rope haulage systems is the possibility of generating slack rope during deceleration. This paper illustrates the issues involved in designing a system so as to avoid the possibility of slack rope. In conclusion, the key factors relevant to the selection of endless or direct rope haulages for a particular decline application are reviewed. The paper is a joint submission by FFE Minerals-Vecor and Qualter Hall UK.

Jan 1, 2005

By O Arafat, R E. McIvor, K M. Bartholomew

It is well known in the industry that good classification system performance is vital to efficient ball mill circuit performance. But what is meant by good classification system performance, and how is it achieved? Unfortunately, the perceived complexity of classification systems, and the day-to-day time demands placed on the practicing metallurgist, all too often put the low-hanging fruit of classification system optimisation in the ‘I’ll do it later’ basket. Additionally, lingering confusion about basics such as the relationship between circulating load ratio and ball mill circuit performance makes the optimisation objective seem nebulous to both plant metallurgist and designer.Some of this confusion can be eliminated by taking a step back from the overwhelming detail of sharpness of separation curves, circulating load ratios, cyclone feed pressures, vortex and apex sizes etc, and focusing on the purpose or function of the classification system – to apply mill power to particles that need further size reduction! The classification system efficiency (CSE) metric captures how well the classification system is performing its function with two quick and easy size distribution analyses.Once CSE is understood and implemented as the optimisation criteria, well-tested methods for improving CSE can be implemented and quickly measured at plant scale to give confidence that the right change was made.This paper will describe CSE and how it is measured in practice. Next, a guide for improving CSE through manipulation of design and operating variables in the classification system will be provided. Examples and case studies will illustrate the gains in ball mill circuit efficiency that can be achieved by maximising CSE.CITATION:Bartholomew, K M, McIvor, R E and Arafat, O, 2018. A guide to maximising ball mill circuit classification system efficiency (CSE), for operators and equipment designers, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 553–558 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By K Knorr, S Birch

The mineralogy of new certified-reference-materials (CRM) for X-ray fluorescence from Western Australia (ASCRM 030 to 035) was analysed by X-ray diffraction using the BRUKER energy dispersive one-dimensional detector LYNXEYE-XE. The samples were studied using standard-less quantitative phase analysis, based on the Rietveld method. This method delivers the relative amount of crystalline phases. All materials were found to be high-grade iron ore predominantly consisting of hematite and goethite and very low amounts of magnetite. In addition, the gangue mineralogy was characterised. It consists of low-per cent amounts of carbonate (siderite/calcite), quartz, kaolinite, chlorite and gibbsite.Furthermore, all samples were analysed with the external standard method. This is an elegant way to probe for amorphous content without adding an internal standard. All six samples were found to contain up to 16 per cent amorphous or nano-crystalline material.CITATION:Knorr, K and Birch, S, 2013. Mineralogy of new Australian x-ray fluorescence standards, in Proceedings Iron Ore 2013 , pp 269-274 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By R Baumgartner

The Canahuire deposit is a recently discovered Au-Cu-Ag epithermal deposit in Southern Peru. A geometallurgy program is a key study element of the project Feasibility study. Metallurgical, mineralogical, and comminution studies have been completed over a suite of samples, spatially distributed among the various geological/ore domains. The early stage of Canahuire presents challenges as there is a lack of metallurgical information to guide geometallurgical sampling, in contrast with an established deposit at a more advanced stage of development or mining. Nevertheless, the available information will assist in the development of geometallurgical domains for Canahuire in order to ensure that future metallurgical, mineralogical, and comminution test work is representative of the deposit variability. This supplementary knowledge will be able to predict important metallurgical parameters which will be incorporated into a geometallurgical model to spatial predict material types, metallurgical recovery and through put. The information obtained will be a valuable addition to the future mine plan, influencing process design, engineering design, plant operation, operating and capital costs, and ultimately will reduce project development risk.

Sep 5, 2011

By J P. Evert

Didipio gold-copper mine operation is situated in the island of Luzon, approximately 270 km north of Manila in the Philippines, in an area of high seasonal rainfall. The hydrogeological water flow model implied that there would be high connectivity between regional structures and underground operations. This model predicted that underground mine groundwater inflows were expected to quickly rise as the decline progressed to a peak of 510 L/s. Designing a capital pump station to deal with 510 L/s has its own challenges, however developing the decline down to the required level, always dealing with 300 L/s of water and constructing the pump station is extremely challenging and required a robust water management plan and mine design. When dealing with expected high volumes of water, underground mine design and scheduling plays a key role in protecting electrical infrastructure, equipment, secondary pumps, and the decline from flooding. A good drainage system and controlled dewatering plan is essential for safety and progress. This paper details the dewatering techniques and mine designs required to accomplish decline development with high water inflows as used in the Didipio project. It will describe the learnings and outcomes that are achievable with a flexible design, as new structures are mapped, and water intersections are increased. It also highlights the potential for adaptability in mine planning to provide evolving improvements or to evade problems that are expected from the constant reconciliation of data recorded during development.

Mar 29, 2023

The Kalgoorlie Golden Mile is proposed as an Archaean volcanogenic-type deposit, modified and redistributed along later-developed structures. Rich pyritctelluride and Green Leader gold mineralization is associated with the end phase of basic volcanism and, in a general sense, is confined to a broad interface zone between the products of marine basic volcanism and later acid volcanism. There is virtualIy no ore associated with the main body of acid volcanics.Green Leader is the local name of a type of ore that occurs at some igneous rock contacts in association with graphitic sediments and layered acidic tuffs. It is characteristicalIy green, of various shades, and commonly yields very high gold assays, the reasons for which are not apparent in hand specimen.Carbonates, carbonaceous shales, tuffites, rich gold ores, and acid and intermediate dykes, alI indicating a common heritage, are features common to the main ore hosts, viz. the Paringa Basalt (Calc Schist) and theGolden Mile Dolerite ("Quartz Dolerite Greenstone").Several probably related fracture systems have reconstituted most, but not all, of the original deposits into a large number of steep tabular lodes.Includes two sets of discussions and comments from later Proceedings volumes.

Jan 1, 1974

By X Feng, X Zhang, W Sun, Y Zhe, K Hou, B Zhao, H Liu

Pulang Copper Mine, being China's largest newly built mine using block caving, boasts an annual production capacity of 12.5 million tons. Production level and roadway stability hold the key to the successful application of block caving. However, with Tong Kuangyu being the only mine in China which has applied such a method, we currently lack relevant experience in the successful application of the method. This paper has studied the influence of different rock mass zonings, fault thickness, fault dip angles, on-site construction quality on the production level, roadway stability of block caving through numerical simulation and analysed the roadway stability in different kinds of support solutions so as to ensure the successful application of block caving in Pulang Copper Mine. The results have shown that the existing support method in Pulang Copper Mine can meet the requirement of roadway support in zone II and III, but could not satisfy the demand in terms of support strength in the relatively fragmented zone I area. When roadway passes through the fault, the deformation of surrounding rock and plastic zone of roadway will gradually decrease with the increase of fault dip angle; the deformation of surrounding rock and plastic zone of roadway will gradually increase with the increase of fault thickness. An ideal support effect can be achieved through the joint support of grouting and bolting when roadway passes through the fault. In the measured model of on-site construction, there is stress concentration in the intersection between the access and transverse drift of ore removal. Therefore, the stability of the roadway can be improved by improving the construction quality. CITATION:Sun, W, Hou, K, Zhang, X, Feng, X, Liu, H, Zhe, Y and Zhao, B, 2018. Research on supporting technology for production level roadways of block caving in Pulang Copper Mine, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 95–106 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

By B N. Noller, J C. Ng, S L. Bruce

Mining activities can result in the transfer of harmful elements, including arsenic and lead, into the environment. In Australia, one of the potential future uses of rehabilitated mine land is to stock grazing animals. Elemental uptake is dependent on bioavailable fraction for adsorption upon exposure. Bioavailability data are generally lacking in order to provide realistic health risk assessments relating to harmful elements from mine tailings in Australian conditions. Another key component of risk assessment is the ability to estimate a realistic exposure, or dose rate, of the tailings to the grazing cattle over a set period of time. Hence, we aimed to conduct grazing trials directly on rehabilitated tailings facilities in order to provide valuable in situ information on heavy metal dose rates and associated accumulation. For the laboratory-based evaluation of comparative bioavailability, groups of cattle were fed five days a week on a normal diet spiked with mine tailings or soluble pure salts of target elements (eg sodium arsenate, sodium arsenite and lead acetate) for about eight months. For the field validation, cattle were allowed to graze directly on rehabilitated tailings facilities over a similar length of time. Blood and a biopsy of the muscle and liver were periodically collected to monitor arsenic accumulation. At necropsy, blood, muscle, liver, kidney and other saleable tissues were measured for arsenic concentrations. Although this study was focused on arsenic, lead and other metals were also measured. Predictive models for arsenic and other metals have been established to calculate the maximum grazing duration without the risk of exceeding specific food safety guidelines. The outcome of this study is a predictive model for maximum beneficial use of certain rehabilitated tailings for cattle grazing where grazing activities do not impact on the integrity of the tailings dams.CITATION:Ng, J C, Noller, B N and Bruce, S L, 2014. A predictive model for beneficial use of rehabilitated mine tailings for grazing cattle after mine closure, in Proceedings Life-of-Mine 2014 , pp 563–572 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By F Rashidinejad

Iran has had an active mining sector for some 7000 years. Exceptional in terms of its mineral diversity, Iran produces 62 minerals, and is ranked among the world’s 15 most mineral-rich countries. Many people around the world know Iran as one of the major petroleum exporters. Oil and natural gas dominate Iran’s economy, and oil exports provide the principal source of income, contributing more than 80 per cent of foreign exchange earnings. Transformation of Iran from an oil exporter to an independent country to oil has been on the table for many years, even before the Islamic Revolution of 1979. Development of the Iran’s mineral industry is one of the major replacements for petroleum exports. In the last decade, Iran invested billion dollars in the mining and mineral industry sectors and to increase the added value, tried to export processed minerals instead of the raw materials. In accordance with the ‘20-year Perspective 2025’ that targeted by the Supreme Leader, Iran will be a country with the first rank in economy, science and technology in its region. The objectives over this perspective include briefly increasing annual production to 55 Mt of crude steel, 800 000 tonne of copper cathode, 1.5 Mt of aluminium, 200 Mt mineral products, 300 000 tonne of zinc and 5 000 kg of gold. These goals are achievable in normal circumstances, but concurrency of the 20-year Perspective 2025 with commencement of the UN Security Council sanctions against Iran, frustrated objectives of the perspective, at least the ones related to the mining and mineral industry sectors. This paper tries to elaborate the development programs and following challenges for the mining activities of Iran by 2025.

Nov 22, 2011

By R Winterberg

Concrete is a well established and reliable construction material for the permanent lining of tunnels, but shows some weak performance characteristics, which can be overcome by the addition of specialised fibre reinforcement. This paper addresses the particular performance design requirements of segmental linings, discussing the improvements of fi bres on concrete properties. Focus is made on the beneficial effects of fibre reinforcement on the cracking behaviour and the toughness performance, providing a safe and durable tunnel lining.Not only the mechanical performance of fibre reinforced concrete (FRC) for segmental linings, but also the durability of the linings has gained growing attention among the designers and consultants. Especially tunnel linings with exposure to media with corrosion potential, such as wastewater sewer tunnels or desalination plant outfall tunnels, have high requirements on their durability. The design of these structures must provide a comprehensive study of durability aspects. Fibre reinforcement can substantially improve the durability of concrete.Research has been carried out on the cracking behaviour of concrete. The beneficial effects of steel fibres on the cracking behaviour reduce the permeability by reducing the flow paths within the concrete. Crack bridging steel fibres create necking effects in bending cracks, leading to earlier closure of the cracks. Further, steel fibres create particular crack formations, which lead to a substantial reduction of the fl ow rates through separation cracks. The results also show that considerable cost savings can be achieved using FRC, as the thickness of the linings can be reduced.The durability design issues will be addressed and underlined by a case history on the Hobson Bay sewer tunnel in Auckland, New Zealand.

Mar 8, 2011

By A Esfahanipour, M Osanloo

Determination of cut-off grade?strategy is one of the most important stages of open pit mine planning and design. It is the parameter directly influencing the financial, technical, economic, legal, environmental, social and political issues in relation to mining operation. Choosing the optimum cut-off grade strategy that maximises the economic outcome has been a major topic of research workers for nearly one century. Many researchers have contributed in devising methods and algorithms, such as dynamic programming, linear programming, optimal control and so on for various aspects of its determination. In this paper, a non-linear mathematical programming for cut-off grade strategy optimisation is presented, considering the three main stages of mining operation introduced by K F Lane. In this model maximisation of net present value of mining operation, under the three constraints of mining stagesÆ capacities, considered as the optimisation criteria. Due to the discrete representation of the mining resource, the proposed non-linear formulation is approximated by a non-linear signomial geometric programming. According to non-convexity and the complexity of the proposed model, an augmented Lagrangian genetic algorithm was used to find the optimum cut-off grade strategy under varying and fixed price circumstances. To validate the proposed non-linear model efficiency, the results were compared with the results obtained by the K F Lane methodology. It was found that the proposed non-linear model works efficiently in the determination of cut-off grade strategy. According to the simplicity of the structure of non-linear programming modelling in comparison with dynamic programming it is hoped that, further development of this model would certainly provide the ability of considering managerial and technical flexibilities as well as incorporating more real mining conditions in the determination of cut-off grade strategy optimisation.

Sep 26, 2011

By M Hourn, G Anderson, V Lawson, P Voigt, D Mallah

As mine head grades decline and orebodies become more complex, traditional mineral processing techniques and flow sheets to achieve saleable concentrate become more difficult to design and construct. Mines with lower quality concentrates or concentrates with penalty elements are particularly under threat. The economics of such operations are far more susceptible to metal price fluctuations, concentrate treatment terms and the availability of other, cleaner concentrates. Additional value may be realised for these orebodies through improved recovery by producing a low grade middling concentrate for further processing, in conjunction with a saleable concentrate.The most economic effective way to reduce impurity levels is to do so as early as possible in the mining value chain. Technologies such as fine grinding and fine particle flotation are well established as effective methods for impurity rejection in mineral processing. What is often overlooked is how a hydrometallurgical process could also be integrated in the overall flow sheet to achieve higher overall recovery at the mill. In the base metals environment, this is probably because hydrometallurgical processes are associated with production of metal, or require the use of expensive and toxic precipitating agents once the minerals of interest are in solution. These processes can be very expensive, particularly with rising power costs and poor economies of scale in capital costs associated with low production rates from middling streams. Glencore Technology (GT) has recent experience in the treatment of middling and low grade concentrate streams and also tailings streams to complement a concentrator flow sheet in a refractory gold and base metals setting. The value proposition is the isolation of a low grade middling concentrate from the primary circuit or the tailings stream for upgrading to an intermediate product with an equal or higher grade than the primary concentrate to allow blending for sale. This allows the plant to operate on a more favourable part of the grade-recovery curve while avoiding the expense of metal production. For existing operations this is particularly attractive since it can be added to the flow sheet with no process interruptions. Two case studies are examined showing flow sheets and costings to arrive at the value proposition of the GT low grade treatment flow sheet.CITATION:Voigt, P, Hourn, M, Lawson, V, Anderson, G and Mallah, D, 2017. Economic recovery and upgrade of metals from middling and tailing streams, in Proceedings MetPlant 2017, pp 289–297 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 11, 2017

By K Ehrig, V Liebezeit, Y Li, B Pewkliang, M Smith, E Macmillan

Pre-concentration of low grade ores via the rejection of low/no value materials based on fragment size is the subject of many published papers and studies over the past decade. However, the possibility of upgrading should not limited to low grade ores given the high cost of capital, energy, water, reagents, and ultimately tailings storage across the mining industry. Mining and processing facilities at Olympic Dam consist of an: 1) underground mine where ore is extracted via sublevel open stoping and 2) integrated processing plant located on the surface which produces Cu-cathode, Au-Ag bullion and uranium oxide concentrate. Blasted ore is trucked/trained to underground crushers which produce an ore feed with a product size P80 = -145 mm. Crushed ore is then hoisted to the surface and delivered to the ROM pads via an overland conveyor. The typical copper grade of mill feed is approximately 2 wt%. A rapid assessment of the potential to upgrade Olympic Dam mill feed prior to the ROM pads via rejection of low value materials based on fragment size was completed using existing data. Three separate datasets were utilised to assess the deportment of Cu, U, Au across size ranges of 200 mm down to sub-8 m. Cumulative grade vs cumulative mass distribution graphs for each element were produced. This data clearly demonstrates that Cu, U, Au grades remain constant down to ~212 m, which happens to be the liberation size of the sulfides. Hence, no potential to upgrade the ore stream via rejection of +200 mm - to ~212 m sized materials prior to milling. Mineralisation within the Olympic Dam Fe-oxide Cu-U-Au-Ag deposit (IOCG) occurs as disseminated sulfide grains within granite- to hematite-rich breccias. The typical sulfide grain size is sub-200 m that supports the outcomes of the grade deportment by fragment size study.

Nov 10, 2020

Control of construction projects is the responsibility of the Project Leaders who have the authority to make decisions. Project Controls cost and scheduling systems provide the Leaders with timely information on which to base their decisions.The Client (Owner) will invest up to three per cent of the project cost on Project Controls. To ensure that this investment is effective, the Owner or Manager must have a clear understanding of the information required from the Project controls systems. If appointing a single Managing Contractor, the Owner or Manager must stipulate what is and what is not required from the Project Controls Systems. There are numerous computer programs available for scheduling and cost control and it is important to select systems which best serve the Owner's needs.

Jan 1, 1993