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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 D R. Seaman, Y Peng, F Burns, D J. Bradshaw

Telfer Gold Mine is a gold-copper mine in the eastern Pilbara of Western Australia, owned and operated by Newcrest Mining Limited. TelferÆs ores are processed by a dual train, 21 Mt/a, concentrator where gold is primarily recovered by gravity concentration and the flotation of a gold-bearing copper concentrate. A minor portion of TelferÆs gold is also recovered to a pyrite concentrate that undergoes treatment via carbon-in-leach (CIL) cyanidation. The gold recovery of the CIL circuit is below the industry standard and operates with a high reagent consumption rate.With a new fine-grinding facility, the Telfer process plant will have the ability to liberate copper and gold from the pyrite concentrate and recover these by flotation prior to the existing leaching circuit. This process will improve overall gold and copper extraction, while reducing reagent consumption in the CIL circuit.This article is an overview of the development of this methodology. Size-by-size analysis and mineralogical studies of monthly composites identified factors limiting the CIL gold recovery and the causes of high reagent consumption. Laboratory studies confirmed a relationship between the regrind product size and gold leach recovery. The addition of an intermediate flotation stage ensured that the regrind circuit will improve overall recovery while at the same time reducing operating costs. Without the addition of a flotation stage, the additional reagent consumption from regrinding alone would be prohibitive towards increasing recovery. Pilot scale studies confirmed the conditions required to selectively recover gold and copper from the pyrite concentrate as well as establishing the full scale regrinding energy requirements. Construction of this facility at Telfer is currently underway.CITATION:Burns, F, Seaman, D R, Peng, Y and Bradshaw, D J, 2012. Development of a pyrite regrind circuit at Telfer Gold Mine, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 45-52 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By B Besa

Australia is a world leader in the design and operation of mines accessed by the decline method. Literature indicates that a number of metalliferous underground mines using the decline system are also increasing steadily. This increase has generated a great deal of interest in underground haulage systems in future due to the huge costs involved in the development of declines. Studies have also shown that the current method of accessing orebodies by the conventional decline method has proved to be expensive, especially for narrow vein deposits. This is because decline development costs are influenced by mine planning and design parameters as well as available haulage systems that the mining engineer can choose from. The current access method suggests that more waste material is being extracted because of the size of decline openings adopted (5.5 mW and 5.5 mH). Also the conventional 1:7 decline gradient and turning radius of 20 m makes decline lengths, as well as the duration of development, excessively longer. This paper discusses results of a mine design case study with monorail technology as a method of accessing and developing the decline. The proposed system is economical, has high advance rates and offers a significant reduction in capital expenditure. The study compares costs, development metres and the duration of decline development using the monorail system with the conventional (truck haulage) access method. Results obtained indicate that the monorail technology has the potential to reduce the decline length by over 62.6 per cent and decline costs by 63 per cent for the case study. The monorail system also reduces the total capital development costs by 22 per cent for the same case study. Due to rapid development resulting from increased advance rates and the shorter decline length coupled with smaller decline openings, the time to access the deposit reduced by 71.8 per cent. This case study demonstrates that the economics of narrow vein deposits can be improved significantly by using the monorail system of decline development.

Jan 1, 2008

By P Gehrke, S O’Gorman

The precise measurement of NO2 was historically difficult in road tunnels, hence criteria and design analysis was based on converting from NOx concentrations via a set NO2:NOx ratio. The reliable direct measurement of NO2 is now possible, however design analysis is still dominated by emissions tables and formulas specified in terms of NOx. For converting from NOx to NO2 in a road tunnel environment in Australia, the ratio has typically been assumed to be ten?per?cent. This has generally been based on the recommendation in PIARC (2000) and on the ‘average’ value cited in PIARC (1995).Determining this ratio is important as changes in engine technology and in-tunnel pollution criteria along with improvements in CO and particulate emissions control, may mean that NO2 will become the driving factor for future ventilation requirements. Correct selection of this ratio can directly impact the ventilation capacity and system design.Recent research has indicated that choosing a constant ratio of ten?per?cent for all tunnels may not be appropriate. The in-tunnel ratio has been estimated to be as much as 20?per?cent to 30?per?cent and depends on the location in the tunnel, the type of ventilation system and the traffic/fleet characteristics. This paper discusses the effect of some of these parameters on the NO2:NOx ratio in road tunnels.The findings indicate that the ten?per?cent upper limit on the NO2:NOx ratio in PIARC (2000) may be a conservative value for design purposes for longitudinally ventilated road tunnels of typical length in Australia. A value of seven?per?cent to eight?per?cent may be more appropriate in some circumstances. However, the value chosen will depend on the specific tunnel in question and the confidence in traffic conditions expected. Values above ten?per?cent may be encountered for short periods but usually when the NO2 levels are low.CITATION:O’Gorman, S and Gehrke, P, 2014. NO2:NOx ratios in Australian road tunnels, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 95–102 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By J Hutchings

An essential component to the management of any process is the measurement of key parameters, used to monitor, control, and provide the feedback necessary for improvement. This paper discusses how data collection and analysis can provide a better understanding of the blasting process, as well as additional control and improved outcomes.The drill and blast process involves the generation and use of information at a number of levels. Comparison of historical parameters and results provides a starting point for the development of ongoing blast designs and a baseline against which future results can be compared. The collection of data during implementation provides a quality assurance/quality control (QA/QC) function where potential defects (such as under-drilled or over-charged holes) can be rectified prior to firing. Actual quantities and production rates allow the development of realistic plans and schedules, rather than using inaccurate estimates and targets that lead to unscheduled changes to equipment paths. Over?the past several years there have been a number of technological advances in data collection technology. Drill monitoring instrumentation on blasthole drills provides location information and feedback on rock properties as drilling occurs. Hand held ‘data logger’ technology has also overcome the challenges of working on the bench, such that blasthole measurements can be collected and forwarded directly to the explosive truck. Mine sites are becoming wireless network-enabled allowing the seamless data transfer from the field back to the office, in near real time, as that information is collected. Great strides have also been made in the development of drill and blast software systems which are more user friendly, and yet provide far greater capability to manage the quantity of data generated. The blasting process is critical to the overall mining process and the delivery of a successful blast outcome requires that the blasting process be ‘in control’. The measurement of key parameters can provide the data with which to measure and maintain control of blasting, and allows the validation of performance improvement measures and identification of improvement opportunities.

Nov 8, 2011

By A A. Latscha, D O’Connor

Increasing orebody complexity, restrictions in ground access, and longer lead times for disturbance approvals, have generated the need for the Resource Development Team within Rio Tinto Iron Ore (RTIO), to explore optimised drill design techniques that deliver resource conversion value while maximising program outcomes. In response to this challenge, the Team initiated a case study to produce an AI assisted/designed drill program using a non-machine learning AI. The case study involved the assessment and implementation of an AI generated drill program at one of RTIO’s Pilbara iron ore deposits, located in the Hamersley Province of Western Australia. The Mineral Resource is currently classified as 100 per cent Inferred. Access constraints inherent to topography, and the presence of exclusions zones have prevented adequate drilling coverage, resulting in lower resource confidence and a poor definition of the orebody extents and geometry. The drill campaign, planned in Q1 2023, needs to consider access constraints, complex topology and the limitations related to additional ground clearance, while addressing the requirement of improving orebody knowledge. The drill plan had to address two objectives. The first and main aim of drilling was to upgrade the Resource Classification to allow for possible conversion to Ore Reserve. The input for this objective was a volumetric representation of the areas currently not meeting pre-defined quantitative Resource Classification upgrade criteria. The second objective was to better define the orebody extents and geometry. For the second objective, the input to the drilling optimiser was a volumetric representation (blocks) of the areas of high uncertainty in the mineralisation/waste boundary, which were defined using an indicator conditional simulation technique. The drilling optimiser output was a range of compliant drill plans. A set of KPIs based on economic and orebody knowledge criteria were used to assess the plans and to select the most optimal drill design to be drilled in 2023. The geology and management teams were able to make better informed, objective decisions using the trade-off between cost and orebody knowledge gained. As part of the assessment, the AI generated plans were compared to our current planning practises. The AI assisted plans, when gauged against the project KPIs, showed clear and measurable improvements in both meeting project objectives and in managing operational risk.

May 24, 2023

By Harada M, Katsuta S

In order to shorten the time taken to com- plete shield tunnel excavation work, reduce labor costs and to improve safety, an automatic assembly robot system for the segments used has been developed. It was developed in the three years from 1982 until 1984. An experimental assembly system for concrete segments (outer diameter:.3.55m) has been thoroughly tested to confirm that these segments can be fed and assembled automatically (Fig. 1, 2). This report outlines the robot which will be put into practical use in the near future. The robot senses the position of already assem- bled segments by means of position sensors, controls the position and the attitude of the segment to be assembled to allow bolt hole positioning, and completes the automatic assembly of a se;nent by automatically tighten- ing bolts. The six segments which make up one ring can be automatically assembled in about 25 minutes.

Jan 1, 1987

How often does one hear that a recent feasibility study was not a success? Alternatively, when scope of the feasibility study was sent out to tender there was a large discrepancy in tendered prices. If the tendered prices were to be compared to the consumer market, for instance the purchase of a car, where the concept is transport in a controlled and safe manner, prices vary by large factors, but then so do the specifications. In the case of a feasibility study, prices should be within a tighter margin as the tenderers are all quoting against the same concept and specification. Why do these discrepancies occur? Price discrepancies will in every likelihood be attributed to two main factors; one, the perceived amount of work and two, the ability of the bidder to carry the risk associated with the feasibility study. It is, therefore, important that the scoping of the feasibility study covers the detailed requirements as clearly as possible stating what level of accuracy is required. The feasibility study is one of the first activities in the life of a project. The study, like the project it is investigating, is subject to the constraints of time, cost and quality. Its primary objectives are to demonstrate the viability of a project within the outlined scope and constraints.

Jan 1, 1998

By R Shelton

The Big Wainihinihi River and tunnel are located on the western side of the Southern Alps of New Zealand within the active Alpine Fault zone, which marks the boundary between the Pacific and Australian Tectonic Plates. The tunnel was built over 100 years ago to supply water for gold mining, but it now conveys water from a high-energy intake to a canal that supplies three of TrustPower’s hydro-electric power stations with a combined installed generating capacity of 10 MW. Part of the tunnel passes through an unstable 50° schist slope, which fi rst suffered a wedge failure in the 1929 Arthur’s Pass Earthquake and was reinstated in the mid-1970s for hydro generation. In 2008, TrustPower’s monitoring system showed that the wedge failure had remobilised and that urgent remediation was required.Harker Underground Construction (Harker) was awarded a design-build contract to restore the tunnel to service by tunnelling a new central section. Their geotechnical engineers, Peters and Cheung, reviewed the tunnel’s stability and proposed a new, safer tunnel alignment, deep behind the failure wedges. This work was based on their failure model, cost-benefit studies, and engineering geology completion mapping at the time of re-opening.Construction innovation was an important factor in ensuring the project’s success, as were detailed geological and geotechnical information, a robust methodology, strong client relationship and planning. To suit the varying rock conditions and restricted space, Harker combined a traditional drill-and-blast method with light-weight modular steel sets and timber supports to reduce construction costs and mitigate support risk. To make material handing easier in the tight conditions, a special electric locomotive was designed and built and blasting confi gurations were adapted to suit varying rock conditions in the highly fractured schist.The isolated site meant interesting and unexpected challenges, particularly communications and resources (both human and material). Despite that, the project was completed within budget, on schedule, and with no lost-time injuries.

Mar 8, 2011

By Resta S. A

Energy Resources of Australia Ltd - Ranger Mine is located about 255 kilometres east of Darwin in the Alligator Rivers Region of the Northern Territory. The Ranger project is surrounded by Kakadu National Park which is on the UNESCO World Heritage list. . Ranger Mine operates the largest uranium mine and processing plant in Australia. It is designed to produce 3000 tonnes of uranium oxide per year, but presently is producing a little less than one half that figure due to the depressed uranium market. The safety performance of the employees and Ranger as a whole continues to improve. The lost time injuries (LTI) have significantly reduced from 74 in 1985 to five in 1994. The total days lost due to LTIs have gone from 1543 to 14. These significant improvements have reflected directly on workers' compensation premiums in which a four-fold reduction has occurred. It is estimated that the actual monetary saving to the company is about $1.3 million per year and directly reports to the profit of the company. There is also an obvious and significant reduction in the less quantifiable costs such as the suffering of the injured employees and cost to society. The paper will review the various initiatives introduced and assess their effectiveness. Performance improvement is primarily dependent on the commitment, introduction of various initiatives and the subsequent change in workplace culture.

Jan 1, 1994

Brief summary of results obtained by a French-Japanese cooperative study on the bottom of trenches around Japan. The geophysical prospection, multi beam echo sounding and direct observation with submersible dives of the trench bottom clarified the details of the subduction of oceanic plates. It may be noted, among many new facts found: 1. The subduction and geologic structure resulted from the process is different according to the nature of subducting oceanic plate, and the geology of the land behind the trench. Thus the Nankai trough characterized by the developpement of accretionary prisms is contrasted to that of the Japan Trench where the basement rocks are exposed on the land side cliff of the trench wall. 2. The compressional tectonic situation prevailing in the trench bottom provokes the venting, along the fissures on the bottom, of water contained in sediments. Hydrocarbons contained in the sediments are comming out with water and give nutrients for bacteria. Clams, tube warms, sea slugs and shrimps are taking these bacteria as their food and biological communities with exceptionally dense population for the deep sea of more than 3000 meters in depth are formed on the field of accretionary prism and wall of the land side cliff. 3. An intense compressional tectonic field resulted from the subduction is inducing the transition from the subduction of oceanic plate to the collision of a part of the plate to the continental plate.

Jan 1, 1987

By P Holtham, K C. Runge, E Tabosa

Traditionally, comminution and flotation have been surveyed, analysed and optimised separately. This often results in less than optimal outcomes because of the complex interactions between the two processes. Flotation recovery is a strong function of the valuable mineral particle size distribution with lower recovery of ultra-fines due to poor flotation kinetics, optimum recovery for the intermediate sized particles and lower recovery for the coarser particles due to poorer liberation. Thus, to optimise flotation recovery and grade it is usually best to grind to a fine size. This requirement needs to be balanced by the cost of grinding finer and the revenue that results from an increase in grinding throughput, which often results in a coarsening of the flotation feed.This paper demonstrates a technique which can be used to predict the effect of a change in feed grind size on flotation performance. It can be used to determine the optimum grind size for a particular operation which optimises total circuit profitability. Analysis is relatively easy to perform, as a minimum, requiring only size by assay data of the feed and product streams of the process. Case studies will be presented that demonstrate the usefulness of this technique in feed grind applications. Potential use of the technique for regrind evaluation is discussed. The limitations associated with this technique in certain circuit scenarios will also be outlined.CITATION:Runge, K C, Tabosa, E and Holtham, P, 2014. Integrated optimisation of grinding and flotation circuits, in Proceedings 12th AusIMM Mill Operators’ Conference 2014 , pp 77–84 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 1, 2014

By M Norbert, P Mok

The mainline running tunnels for Legacy Way comprise of two-lane tunnel boring machines (TBM) driven tunnels. The length of the TBM tunnel section is approximately 4.2 km. The TBMs employed are double shield TBMs. Typical support to the segment ring while advancing a double shield TBM comprises of filling the excavated annulus between the ground and the segmental lining by injecting pea gravel, followed with primary grouting to fill between the pea gravel some distance behind the excavated face. The methodology adopted for the Legacy Way project, however, did not follow this typical approach, instead, two component grouting of the annulus was carried out.Where the annulus is typically filled with pea gravel, support is provided to the segment ring very close to the end of the tail shield, whereas in the case of two component grout this is not practical as the risk of grouting in the tail shield is high. The staging of the two component grout injection, the grout early age strength properties become key issues in ensuring that the segment ring leaving the TBM tail shield is stable and can support the necessary external loads.Two-component grout is a grout with two components, cementitious grout (component A) and accelerator (component B), commonly adopted for earth pressure balance (EPB) TBM. The grout reaches its thixotropic state in a matter of seconds providing initial support for the segment rings. Manual injection of two component grout to fill the bore annulus was carried out in stages leaving a portion of the segment rings unsupported. Ring stability during TBM advance was provided by a combination of ram thrust and the segment circumferential joint shear connectors.This paper outlines the design considerations such as rock load derivation by probabilistic analysis carried out utilising the software JBlock, 3D finite element analyses using the software Strand7 for ring stability and the testing and back analysis of the shear connector load bearing behaviour. In particular, the actual available capacity of the shear connectors against their published capacity by supplier was discussed.CITATION:Mok, P and Norbert, M, 2014. Tunnel boring machine excavation stability – double shield tunnel boring machine advance with partially grouted annulus, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 51–62 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By T Ireland, S Eratne, W Newns, P Spies

The approach to risk management during the procurement of major projects often has a significant outcome on the ultimate delivery of a project. The NZ$1.4 B Waterview Connection project is the largest and most complex project yet undertaken by the New Zealand Transport Agency (NZTA) and the procurement process for an alliance contract was refined to provide compliance with the International Tunnel Insurance Group (ITIG) Code of Practice for Risk Management of Tunnel Works (TCoP). The principle of shared risk within an alliance incentivises a common understanding of project risks prior to finalising the alliance agreement and therefore enables superior risk management through design, construction and beyond. Risk management practices need to be instigated well in advance of commercial phases, so that commercial competition does not lead to a significant elevation of project risk. In particular the practice of gaining commercial advantage by taking on a potentially unmanageable level of risk is one of the outcomes to be avoided by the TCoP.During the procurement phase the NZTA placed high value on design and construction mitigation measures proposed in order to address ground risks, as is appropriate for a major tunnel project. In order to achieve alignment on the level of geotechnical risks an Alliance Geotechnical Baseline Report (AGBR) process was developed.This paper describes the measures taken during the procurement process to achieve certainty with respect to outcomes and minimise project risks whilst also achieving value for money. Refinements to the procurement process to ensure compliance with the TCoP prepared by the International Tunnel Insurance Group (ITIG) are described along with the AGBR process applied as part of a suite of measures to achieve a successful procurement outcome.CITATION:Ireland, T, Spies, P, Eratne, S and Newns, W, 2014. Risk management and use of a geotechnical baseline report for a competitive alliance procurement?process, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 553–562 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By T Huynh, K Tungpalan, E Wightman, M Edraki, S Palaniandy

Most preventive environmental management practices promote proactive integrated approaches to waste management. For example, life cycle assessment is often used to find the ‘hot spots’ of environmental burdens. This kind of approach is often based on generic data and has rarely been used for tailings. Besides, life cycle assessments are less useful for designing operations or simulating changes in the process and consequent environmental outcomes. It is evident that an integrated approach for tailings research linked to better processing options is needed.The aim of this Nextmine™ project is to develop new tailings management models by streamlining orebody characterisation, process optimisation and rehabilitation. We present an integrated tailings management approach and preliminary results from a case study. Combined grinding and flotation models were developed using geometallurgical data from the orebody, to predict the properties of tailings produced under various processing conditions. The modelling scenarios based on the case study data provide the capacity to predict the composition of tailings and the resulting environmental management implications. For example, the type and content of clay minerals in tailings will affect the geotechnical stability and water recovery. Clay content will also influence decisions made for paste or thickened tailings and underground backfilling.CITATION:Edraki, M, Huynh, T, Wightman, E, Tungpalan, K and Palaniandy, S, 2015. An integrated approach to proactive tailings management, in Proceedings Tailings and Mine Waste Management for the 21st Century , pp 323–332 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

By D R. Anstey

The growing demand for iron ore from Western Australia has led to an increased focus on the development of magnetite and lower grade iron ore deposits. The need to process and beneficiate the ore from these projects can result in the generation of significant quantities of iron ore tailings over the life of a project. Over the coming decades, the management of iron ore tailings will become a significant aspect of the mining landscape in Western Australia.The tailings generated from iron ore projects differ signifi cantly from other mineral tailings currently produced in Western Australia. Iron ore tailings are generated on a scale not matched by any other mineral process and can often contain asbestiform or potentially acid forming components. New iron ore projects are coming under increased environmental scrutiny because of their large scale operations and the sensitive environments in which they occur. This combination of factors creates some unique challenges for the management of tailings generated by iron ore mining in Western Australia.This paper presents the fi ndings of two studies conducted in recent years to overcome the challenges posed by iron ore tailings. The paper discusses the role of laboratory testing in the development of management strategies for asbestiform minerals in tailings. It also presents a numerical modelling approach for evaluating the rates of rise in the storage of magnetite tailings. The paper concludes by outlining how the findings of these studies can be applied to reduce tailings management costs, lower risks and improve environmental outcomes for the management of tailings from iron ore mining.

Jul 11, 2011

By D Kepert

It is the role of the exploration geologist to create wealth through the discovery, delineation and characterisation of economic mineralisation. This requires a critical depth of geological understanding.Unfortunately, the resource industry is well known for its cyclic nature. Many of the current generation of workers have only ever experienced the boom of the ‘super-cycle’ and are only just discovering the negative side to the business. For the case of the geologist and especially the exploration geologist, the magnitude of peaks and troughs are usually amplified and may become destructive to all parties. During the uptime a healthy stream of exploration good news becomes the staple diet of company releases, in particular those of junior companies attempting to bolster the share price. The geological knowledge and experience gained thus forms a significant and integral part of the value and therefore, future of a company. On the downturn it is often viewed that geologists are a luxury, an optional extra and a burden on the bottom line with companies entering a period of memory loss and myopia.Retention of geological knowledge however remains critical as projects, companies and cycles mature. Beyond exploration per se, this knowledge becomes both fundamental in de-risking and commercialising an asset (through development or divestment) and in positioning the company for cyclic or counter-cyclic opportunities.The growth and retention of this knowledge base is difficult to quantify in terms of direct value but becomes one of a successful resource companies greatest assets. At worst, its loss can lead to millions of investors’ funds wasted on missed opportunities, drilling, or poorly designed plant and mine.But the rocks are around for the longer haul and pay little notice to the vagaries of the scurrying of Man.This paper reflects on some of the authors own observations through 25 years of iron ore exploration, in why it is critical to always rigorously question the prevailing geological (mis)understanding and the technical and commercial benefits which that may bring, and looks forward to the future.CITATION:Kepert, D, 2015. Geology – the affirmative case, in Proceedings Iron Ore 2015, pp 285–298 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

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 Gill L. F, Gleeson HB

This paper describes the development of a Computer Aided Design and Drafting based mine planning system in the State Electricity Com- mission of Victoria. The system combines a commercially available CADD system with a commercially available mining/geological package. The methodology used in the establishment of the combined system, the fea- tures of the system and the current status of development are discussed.

Jan 1, 1989

By Bhattacharyya A. K

A major constraint on sustaining high rates of production in the collieries of the Southern Coalfield of New South Wales is the inability to develop panels fast enough to match the rates of extraction. This inability is particularly crippling in the case of retreat longwall mining and is due to nearly half the time in roadway drivage being spent on strata control operations such as roof support.Increased rates of roadway drivage and significantly improved roadway stability can be achieved by the application of yield pillars between parallel roadways. These pillars are designed to yield immediately upon formation and transfer the damaging roof loads away from the immediate vicinity of the roadways. Since the width of the yield pillar is the key to their successful application, it was determined through the Yield Pillar Experiment conducted by Kembla Coal and Coke Pty Ltd at West Cliff Colliery.Three experimental headings, each nominally 5.5 m wide and 2.8 m high, were driven to form two tapering pillars. The width of these pillars progressively decreased from 24 m to 3 m over a length of 154 m. The convergence between the roof and floor of the headings measured at various cross-sections corresponding to predetermined widths of the pillars are analysed in this paper to evaluate the stability of the tapering pillars at the different widths.The width of the yield pillar in a three heading development layout at West Cliff Colliery was determined to be 7.5 m.

Jan 1, 1995