Search Documents

By J St George

Much of AucklandÆs transport infrastructure has been developed on surface with little or no consideration of underground options. Current and planned transportation routes are now facing high costs due to land values and increasing environmental resistance to surface development. The option of utilising underground space becomes a feasible investment decision for these links as well as being the only option to develop the rail network within the inner city area. Transportation tunnels offer a quieter, more energy efficient means of getting around with minimal impacts on the surface environment. One of the major impediments to tunnelling is the high construction cost, which is partly related to the risks of encountering unexpected ground conditions and/or the possibility of causing surface ground deformations which could damage structures. The geology of Auckland has had substantial investigation through various studies and projects. The sediments of the East Coast Bays Formation (ECBF) underlie most of the Auckland urban area. It is classified as a soft rock and is a suitable material to tunnel through using either a tunnel boring machine or a roadheader. This paper reviews the limited amount of tunnelling completed in the urban Auckland area, together with the international advancements that have been made in the tunnelling industry. From the known features of the local geology and the problems encountered historically, the likely risks of tunnelling in Auckland are presented and ways in which those risks could be reduced and managed, are discussed. In addition, contractual arrangements between client and contractor are assessed with respect to complicated projects (such as tunnelling), so that the risks can be managed to create efficient infrastructure routes with reduced costs.

Jan 1, 2008

By G Harbort, D Zoetbrood

"The Phu Kham copper-gold operation in the Laos People’s Democratic Republic (PDR) is owned and operated by Phu Bia Mining Limited. PanAust Limited holds a 90 per cent interest in Phu Bia Mining Limited, with the remaining ten per cent held by the Laos PDR Government.The original 12 Mt/a copper-gold concentrator at Phu Kham commenced production in April 2008. An incremental improvement program resulted in a number of circuit changes being incorporated by 2011, including conversion of conditioning tanks to flotation cells and the installation of a Jameson Cell cleaner scalper. In 2012 the Phu Kham Upgrade Project was commissioned to increase throughput to 18 Mt/a. In April, 2013 the Phu Kham Increased Recovery Project was commissioned to maximise performance by debottlenecking the plant IsaMill™ regrind and cleaning capacity.With the variable mineralogy of Phu Kham ore, control of the c concentrate regrind circuit is essential in terms of achieving effective liberation to maintain concentrator performance. On a routine basis laboratory regrind signature plot data is compared with daily surveys of the operational IsaMills™. More extensive surveys are also conducted to determine size distribution on a mineralogical basis and the effect of fine regrinding on pulp electrochemistry and flotation performance. This paper provides a review of the operating performance of the Phu Kham IsaMills™ with regard to power draw, feed and product size distribution, feed per cent solids, mineralogy and pulp electrochemistry. Operating performance is compared with the IsaMill™ signature plot test for predicting performance.Citation:Harbort, G, Zoetbrood, D and McNab, B, 2016. Operating Performance of the Phu Kham IsaMill™, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 39–50 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By T Medhurst

Recent developments in geophysical borehole log analysis using the Geophysical Strata Rating (GSR) are now routinely used in a number Australian coal mining operations. This allows development of 3D geotechnical strata characterisation models for a range of purposes. The availability of this data provides a means to identify relationships between ground conditions and ground behaviour. As a result, several new design methods have been developed to assist in the strata management process such as roof support, longwall shield design and shaft stability assessment. This paper outlines these methods and provides examples of their application. CITATION:Medhurst, T, 2018. Geotechnical strata characterisation using geophysics and its application for coal mine design, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 420–433 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

By D Baas, J Le, R Braun, R Chandramohan, K Hollis, G Lane

The Phu Kham Copper-Gold Operation (Phu Kham) is located in northern Laos, approximately 140 kilometres from the capital, Vientiane. The operation is a producing asset for Australian-based copper and gold producer, PanAust Limited (PanAust) and is operated by Lao-registered company, Phu Bia Mining Limited (Phu Bia Mining). PanAust holds a 90 % interest in Phu Bia Mining. The Government of Laos owns the remaining 10 %.The Phu Kham Operation has recently undergone a series of process improvements to treat the anticipated competent ores scheduled for 2017 and 2018. The operation’s comminution circuit, which comprises a semi-autogenous (SAG) mill and two ball mills, each with 13 megawatts (MW) of installed power, was expected to be SAG mill limited when treating competent basement rock. Ausenco Services Pty Ltd (Ausenco), was engaged to help optimise and enhance the productivity of the Phu Kham comminution circuit over an eight-month period. The work involved participating in and overseeing the redesign of the SAG mill liner systems and developing operational strategies for maximising throughput through to the end of mine life. Ausenco’s comminution optimisation tool, Ausgrind, was used to benchmark and analyse plant data with empirical models, predict circuit performance for varying ore characteristics and evaluate liner wear and predict the life for varying operating parameters. Variances between the actual and the predicted values were assessed in detail to identify missed opportunities, and guiding operating parameters were redefined to maximise throughput and productivity. In combination with the redesigned liner system, optimised process controls for varying ore competencies, and improved operational practices and troubleshooting strategies, increased Phu Kham overall production, exceeding the milling capacity when treating competent ores. CITATION:Chandramohan, R, Braun, R, Lane, G, Hollis, K, Le, J and Baas, D, 2018. SAG mill optimisation and increasing throughput at the Phu Kham Copper-Gold Operation – a success story, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 113–128 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By B Broad

"Establishing ventilation in the early stages of a new mine is an essential step to achieve scheduled outcomes that ultimately drive the financial success of an operation. If the primary ventilation is not in place in time to support a contractorÆs work output, then the ore delivery is likely to be severely impacted. Options to increase ventilation in order to address shortfalls are limited. This in turn can lead to reduced revenue generation at a time when a mine is at its highest capital outlay. This can have implications for any company, but even more for an explorer moving to producer. The ventilation put in place to cover the start-up period is also unlikely to cover any extended or increased load required to meet schedule delays.The following paper examines two issues in relation to ventilation with a focus on small to medium projects where the company is establishing a mine using a mining contractor. The issues being: potential impacts on the contract and tender process when using a mining contractor key mine design considerations, such as æcrunch timeÆ, as they interact with ventilation achieving a successful ramp up.A recommendation is made for higher levels of detail around secondary ventilation leading up to the primary fan installation. The information should be included as part of the tendering process and preliminary project execution planning. Understanding the æcrunch timeÆ concept can lead to strategies, as well as back up plans, to minimise any negative impact.By understanding key risks around primary ventilation establishment for a new mine, detailed design work can be completed where it is needed most. Value is added by reducing uncertainty and a payback with better contract terms and a more robust ramp up plan. This will improve the economic return for the company and reduce the risk.CITATION:Broad, B, 2013. Contract considerations and other critical ventilation aspects in achieving a new mine ramp up, in Proceedings The Australian Mine Ventilation Conference, pp 207-214 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 1, 2013

By M Kent, D Elder, J Woodward, R Edwards, B Catto

At Tropicana gold mine (TGM), mine planning is completed from ‘one source of truth’ known as the Integrated Planning Model (IPM). The IPM is a block model which forms a core component of the TGM Mine Planning System – used for short, medium and long-term mine planning cycles, and for Mine to Mill reconciliation.The IPM was developed from a desire to consolidate long-term information contained in mineral resource and ore reserve models, with short-term information from the grade control processes, including grade control models and ore polygons.The IPM is informed initially by resource models, upon which the longer term budget and schedules are based. The IPM is routinely updated with grade control models and ore design information, providing increased confidence for short to medium term mine planning. In this format, the IPM also provides a framework for reconciliation of resource performance with grade control, mining actuals and mining schedules, and ultimately milling. As well as a means for analysing past performance through reconciliation, it has proven its worth as a predictor of variation and an input to successful schedule sequencing and change management. The IPM is a critical component of the TGM Mine Planning System, providing a centralised framework for short interval mill feed prediction through to life-of-mine (LOM) planning.Current development of the IPM is working towards incorporating Mine to Mill optimisation and real-time material tracking projects at TGM. If successful, the model will provide a truly powerful mine planning data source. Current development outlines a mechanism for tracking material from Mine to Mill, and for transferring mill performance data back to the IPM. Increasingly advanced material classification and mine planning, incorporating the multiple geometallurgical variables, will enable the mine to provide consistent mill feed products and result in a steady state and optimised mill.This paper outlines the vision, creation and benefits of the IPM at TGM. It also introduces the ongoing developments to ensure the IPM becomes only more relevant to successful and integrated mine planning as TGM matures from the new kid on the block to the old hand in the neighbourhood.CITATION:Catto, B, Elder, D, Edwards, R, Kent, M and Woodward, J, 2017. An integrated approach to mine planning – building the integrated planning model at Tropicana gold mine, in Proceedings Tenth International Mining Geology Conference 2017, pp 305–314 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

By P J. Cullen, B P. Banerjee, S Raval

Continuous monitoring of mining impacts on the surrounding environment is a necessary sustainability criterion. Traditional monitoring approaches such as in situ sampling and airborne and satellite-based remote sensing have several limitations. Over the past few decades, unmanned aerial vehicles (UAVs) have evolved into popular platforms for remote sensing. UAV-based remote sensing has been successfully applied in different sectors, including agriculture, forestry, urban environments and disaster management. However, the potential of UAVs for mine environmental monitoring has not yet been fully established. This paper envisages the use of UAVs and sensor systems to monitor the environment of future mines.CITATION:Banerjee, B P, Raval, S and Cullen, P J, 2015. Unmanned aerial vehicles for mine environment monitoring, in Proceedings Third International Future Mining Conference, pp 137–144 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

By J Player, R de Vries, E Villaescusa, H Saw, R Hassell

The use of cemented rock fill (CRF) for support of open stope walls has increased in the Australian underground mines operations over the last five years due in part to its low capital cost. In open stoping the exposed CRF masses require adequate strength and stiffness, in order to resist the forces and to limit the displacement associated with movements in the rock mass surrounding the excavations. The CRF material preparation often involves the use of large particles, either from crushed rock or from development mining waste sometimes up to 1 m in diameter. However, the use of waste rock, which has a poorly graded particle size distribution may not achieve the required minimum target strength due to segregation and large air voids within the fill mass. This paper describes the optimisation of CRF strength by either crushing the waste rock or the addition of sand to the mix. Both methods increase the level of fines in the mix design. Cylindrical samples having 400 mm diameter and 800 mm heights were prepared for uniaxial compressive strength (UCS) testing. The UCS test was determined using the Western Australian School of Mines (WASM) large-scale static test frame. The laboratory results were compared with a database of large-scale CRF strength mixed without sand from a number of mine sites around Australia. The comparison shows a significant strength development in the CRF mixing with addition of sand for a given cement percentage. Due to the higher strengths achieved by the addition of sand and the crushing of the waste material these CRF types require less cement to achieve the same strength. This has the potential to improve the overall economics of open stope mining due to less dilution of the exposed fill mass.CITATION:Saw, H, de Vries, R, Player, J, Hassell, R and Villaescusa, E, 2017. Optimisation of cemented rock fill strength for open stope support, in Proceedings 13th AusIMM Underground Operators’ Conference 2017, pp 85–90 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 16, 2017

By C A Heinrich, Morse M. P, Cruickshank B. I, Pyke J. G, Whitaker A

Very little public domain information is available on the exploration signature of the Coronation Hill Au+Pd+Pt deposit. From 1987 to 1990 the BMR (now AGSO) carried out geological, geophysical and geochemical (whole-rock, stream, soil and rock chip) surveys within the South Alligator and Kakadu Conservation Zones and defined several key parameters useful for exploration programs. The essential geological ingredients for the style of Coronation Hill Au+Pd+Pt¦U deposit are oxidised, low pH fluids, dilatant fault structures, a thick neutral to oxidised cover sequence and chemical traps in the basement. In geophysical data, the areas surrounding the mineralisation can be detected by airborne magnetics as major lows in magnetite-rich rocks, whereas in airborne gamma-ray spectrometry data, imaged spectrometric channel ratios such as U2/I'h and U2/K highlighted alteration surrounding the deposits. Three types of stream-sediment and soil samples were taken from each site: (1) -1 mm mesh, 5 kg sample for bulk cyanide leach (BCL) analysis for Au, Pd, and Pt; (2) 1 kg sample of -1 mm mesh sediment for fire assay/ICPMS analysis for Au, Pt and Pd; and (3) 50 g - 180¦ mesh sample for a variety of trace element analyses, including Au, Pd and Pt. Techniques 2 and 3 gave similar results for Au, Pt and Pd, while the recovery rates for Pd and Pt from the BCL samples were considerably lower. Other trace elements did not define unique indicators for Pt or Pd mineralisation, as each sample reflected the dominant lithology in the drainage basin. Rock chip surveys were useful in determining which faults were associated with the ore fluid in regions of multiple fracturing. Results from these exploration-style surveys also confirmed that the Coronation Hill deposit is a variant of the unconformity-style of mineralisation, as all significant geochemical and/or geophysical results occur at or below the unconformity.

Jan 1, 1994

By J Bolen, I Cameron, M Huerta, M Okrutny, K O’Leary

As greater amounts of fine iron ore concentrates enter the marketplace, new investments in iron ore pelletising capacity are inevitable to deliver these concentrates to steel industry consumers. When investors assess the two well-proven pelletising technologies, the straight grate and grate-kiln, the most appropriate choice may not be immediately evident. Certain technical, market and site-specific factors will favour one technology over the other; investors need to be aware and understand these factors in order to make the best investment decision. Hatch has compared the merits of both technologies regarding plant configuration; type of iron ore processed; energy consumption and flexibility to use a variety of fuels; ability to produce the required pellet quality; required plant capacity and scale; operating and capital costs and environmental performance. A technology assessment checklist that investors should consider when making a new pellet plant investment decision is presented.CITATION:Huerta, M, Bolen, J, Okrutny, M, Cameron, I and O’Leary, K, 2015. Guidelines for selecting pellet plant technology, in Proceedings Iron Ore 2015, pp 45–52 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

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 A Murphy

Mining plants and infrastructure, and the decisions made by their designers, can have large impacts on their environmental and social context, commonly referred to as the site or plant footprint. They can also be the source of constructive contributions to sustainable development when designers are enabled via the information, systems and tools to incorporate sustainability in engineering processes. A facility’s footprint and the project’s contribution to sustainability – economic, environmental and social aspects – are now key considerations in regulatory approval processes and are the fundamental drivers of support, or opposition, from the project’s stakeholders.Historically, plant and infrastructure designers have not been well integrated with the environmental and social professionals who are engaged to pursue regulatory approvals. Despite this, many objectives central to technical and process engineering have in fact contributed positively to a facility’s footprint and indeed its contribution to sustainable development. Examples of these objectives include increasing process and energy efficiency, and minimising the quantities of waste requiring disposal. With the framework of sustainability, mining plant and infrastructure designers are indeed at the forefront of incorporating sustainability into resource industry projects and are central to the process of obtaining regulatory approvals and ongoing stakeholder support. The process of incorporation starts with a shared understanding of sustainability and sustainable development, and continues with project processes that facilitate information and knowledge exchange throughout the project life cycle.CITATION:Murphy, A, 2014. Incorporating sustainability into mining plant and infrastructure design, in Proceedings Life-of-Mine 2014 , pp 637–646 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By M Thompson

"The Jaguar concentrator, 60 km north of Leonora, Western Australia (WA), consists of a standard closed circuit semi-autogenous grinding (SAG) and ball mill producing a float feed of approximately 60 micron at 70 t/h. Following comminution, separate copper and zinc concentrates are produced by differential flotation. These concentrates are subsequently dewatered by thickening and then filtration.Separate audits of the Jaguar Operation’s copper and zinc concentrate thickeners were conducted to evaluate their performance, following occasions where site personnel had identified unnecessary loss of copper and zinc concentrate to the thickener overflow. The feedwells were identified as the source of the observed problems due to the following issues with their design/duty:lack of retention time in the feedwell as current design is completely opennot conducive to effective mixing required for efficient flocculationdiameter of the zinc concentrate thickener feedwell was undersize for its duty.To improve the performance of the thickeners, it is planned to replace both concentrate thickener feedwells with a high rate design for their respective duties in February 2016. The audits also identified that the feed system requires modifications with particular importance placed on minimising air entrainment of slurry into the thickener feedwell. Minimisation of air entrainment is hoped to be achieved by providing constant head pressure through installation of weir arrangements in the feedboxes and redirecting each feed pipe so that it feeds tangentially into the feedwell. In addition, improvements to the control philosophy of both thickeners will be made with the installation of an ultrasonic bed level probe and bed mass sensor, in order to make real-time adjustments to the underflow pump speed to maintain steady state operation.Following the feedwell replacement and modifications to both thickeners it is expected that losses of recovered copper and zinc will decrease to undetectable levels. Subsequently it is anticipated that a more consistent, homogenous underflow can be produced for downstream filtration.Citation:Thompson, M, 2016. Concentrate Thickeners Feedwell Replacement, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 273–278 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By S Bluhm, LádeáOliveira, R Funnell

Taquari Vasouras potash mine (Vale Fertilizantes) has many interesting features including virgin rock temperatures of 50¦C at depths of 700 m. The mine has a relatively small shaft system with limited ventilation carrying capacity, which was not adequate to exploit the full extent of the deposit. This limitation was overcome by installing two large-scale recirculation systems with underground reconditioning centres. This paper describes this unique mine ventilation and cooling system and some of its history over the past two decades. The two controlled recirculation systems have been operating safely for some ten years and the use of large-scale recirculation has been a fundamental component in the increase of production and extending the mining further-and-further from the shaft centre. The recirculation systems have played a huge role in the mine profitability and comprehensively extending the mine life. The paper also discusses a number of novel design and operating features such as reverse running pumps for energy recovery. The underground chilled water system design required a number of special safety features in order to minimise the risk of water leakage since this could be catastrophic in a potash mine. This paper describes a good example of a mine in which the final ventilation and cooling system design ends up very different to what was envisaged at the greenfields stage.CITATION:Bluhm, S, Funnell, R and de Oliveira, L, 2013. Controlled recirculation and refrigeration at ValeÆs Taquari Potash Mine, in Proceedings The Australian Mine Ventilation Conference , pp 237-248 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 1, 2013

After considerable input from the mining industry, the Canadian Securities Administrators (CSA) finalised National Instrument 43-101: Standards of Disclosure for Mineral Projects. This Instrument, which became law across Canada on 1 February 2001, applies to all technical public disclosure on mineral projects and requires all technical disclosure to be based on the work of a æqualified personÆ (QP). While the QP is quite similar to the Competent Person in Australia there are important differences when it comes to all disclosure. This paper will summarise the main areas in which the Instrument introduces major changes to Canadian disclosure standards on mineral projects including the role and responsibility of the qualified person; the increased requirements to file technical reports; the incorporation by reference of the October 2000 CIM definitions of resources and reserves and additional rules governing written disclosure of scientific and technical information. In October 2001, eight months after the implementation of NI 43-101, the CSA compiled a list of frequently asked questions (FAQs) and CSA responses to assist mining industry participants and their advisors in understanding and applying NI-43-101. This document has been well received by industry. The CSA plans to update the FAQs when further guidance is requested. Two industry committees have been established to provide the CSA with technical advice on the application of NI 43-101. As recommended by the Ontario Securities Commission/Toronto Stock Exchange Mining Standards Task Force, the CSA has established an external industry advisory committee û the Mining Technical Advisory and Monitoring Committee (MTAMC) û to monitor the application of NI 43-101 and advise the CSA on industry and professional developments. The role of the CSA-Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Working Committee on Reserves and Resources is to ensure that the future changes and updates to the CIM Standards can be efficiently and effectively incorporated in NI 43-101. During this first year, the Canadian securities regulators have seen an improvement in the quality of disclosure on mineral projects, which will increase investor confidence in the industry.

Jan 1, 2002

By M Svartsjaern, D Saiang and K Mäkitaavola

The Kiirunavaara mine is a large-scale (28 Mt/a) iron ore mine located in northern Sweden. The mine is owned and operated by Luossavaara-Kiirunavaara Aktiebolag (LKAB) using sublevel caving (SLC). The SLC area underlies an open pit decommissioned in the 1950s, the current main SLC haulage level is situated at an depth of 1100 m. The main orebody dips 60 degrees to the east with a distinct boundary defining the hanging wall to the east and footwall to the west. Since the 1980s damage has been observed both in the footwall rock mass as well as on the footwall crest of the open pit. Recent investigations indicate that the underground footwall damage is primarily controlled by large-scale slope failure mechanisms. Structurally controlled near-vertical planar shear failures in the upper footwall appear to be driven or facilitated by a step-path like curved shear failure situated in a zone starting ca 250 m, and intersecting the SLC about 100 m above the active mining level. To confirm this failure evolution a pilot underground measuring system has been designed and installed to monitor the expected rock mass displacements indicated by numerical models based on the above mechanisms. The systems consists of 50 m time domain reflectometry (TDR) coaxial cables installed in the footwall both across and away from an estimated damage extent boundary to monitor shear movements along natural joint surfaces. The TDR installation is combined with long extensometers to facilitate differentiation between diffuse shear and rock mass normal expansion. Additionally, a low-tech system of tape extensometer lines are installed in drifts and stopes running perpendicular to the ore strike to monitor horizontal displacements in the infrastructure as the footwall ‘slope’ loses confinement during mining advance when the mined out areas are replaced by caved rock from the hanging wall.CITATION:Svartsjaern, M, Saiang, D and Mäkitaavola, K, 2016. Underground footwall monitoring at the sublevel caving mine – Kiirunavaara, Sweden, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 773–780 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By Lock PR

The Silver Swan nickel mine is located at the Black Swan Nickel Project, 53 kin north east of Kalgoorlie, Western Australia. The Silver Swan orebody is a massive sulphide nickel deposit dipping 70¦ east with an average in situ grade of 14 per cent. Mining of the massive orebody is by Mechanised Ramp Cut and Fill (MRCF). A mining recovery of 98 per cent and minimising dilution are primary goals in extracting the high-grade ore. Placing a distinguishable marker bed (working platform) on rock fill was identified as a key method to achieving these goals. Gravel from a pit located onsite was considered the most suitable material for the marker beds. Research undertaken to design the marker beds using the gravel revealed conventional methods used in mining would not suffice, but that road stabilisation methods could be a viable alternative. Trials used a road recycler to mix cement and gravel in situ and several test beds were constructed on the surface to determine the final design. The trials attempted to replicate a marker bed's life cycle of construction and placement and mucking of ore from the marker bed.

Jan 1, 1998

By D A. Bowman, S Schafrik

With the goal of reducing injuries and fatalities related to haul truck accidents, this research investigates technologies and intervention strategies for improving worker training using a virtual environment (VE). Funded by the National Institute for Occupational Safety and Health (NIOSH), this research specifically focuses on training workers in preshift inspections of haul trucks to avoid preventable defects from causing worker injuries and expensive equipment damage. Improved training in these inspections is expected to increase uptime. The VE developed to train workers for preshift inspections consists of three phases: the virtual tour, the virtual inspection and the shift simulation. The virtual tour introduces information necessary to conduct a preshift inspection by guiding the worker around a haul truck, identifying parts to be inspected and explaining defects to look for. The virtual inspection assesses retention as the worker navigates around a haul truck and identifies defects. During the shift simulation, the worker is shown a simulation of the work shift, which animates severe consequences of any overlooked defects to emphasise the importance of preshift inspections. To provide multiple training platforms, desktop and CAVEÖ versions of the training VE were created. Flux Studio was used to model the environment and to produce Virtual Reality Modelling Language (VRML) files for the desktop version. DIVERSE, an application programming interface, was then used to implement a more realistic version of the VE in a CAVEÖ, a room-sized visualisation system. Initial feedback from mining colleagues indicates that the training VE may replace normal classroom training for preshift inspections in the future. As opposed to PowerPoint presentations and instructional videos, the training VE provides better spatial understanding of the location of parts and incorporates interactive features to actively engage drivers in the learning process, which may result in better retention. Initial feedback also indicates that minor improvements can be made to the virtual tour and virtual inspection phases.

Jan 1, 2008

By P R. Lock

The Silver Swan nickel mine is located at the Black Swan Nickel Project, 53 km north east of Kalgoorlie, Western Australia. The Silver Swan orebody is a massive sulphide nickel deposit dipping 70¦ east with an average in situ grade of 14 per cent. Mining of the massive orebody is by Mechanised Ramp Cut and Fill (MRCF). A mining recovery of 98 per cent and minimising dilution are primary goals in extracting the high-grade ore. Placing a distinguishable marker bed (working platform) on rock fill was identified as a key method to achieving these goals. Gravel from a pit located onsite was considered the most suitable material for the marker beds. Research undertaken to design the marker beds using the gravel revealed conventional methods used in mining would not suffice, but that road stabilisation methods could be a viable alternative. Trials used a road recycler to mix cement and gravel in situ and several test beds were constructed on the surface to determine the final design. The trials attempted to replicate a marker bedÆs life cycle of construction and placement and mucking of ore from the marker bed. Testing the marker bed for strength for use as a working platform was completed using a Clegg Hammer; good correlation to a Clegg Impact Value and the compressive strength of the stabilised gravel was found. This paper describes the use of a road stabilisation machine, tests conducted, monitoring and marker bed design and discusses underground placement of the marker bed and its performance.

Jan 1, 1998

By D Connelly

High purity alumina (HPA) is a processed, premium non-metallurgical alumina product characterised by its purity level ie 99.99 per cent (4N) or 99.999 per cent (5N). The market price, application, and performance of HPA varies widely according to its degree of purity. High purity alumina is a form of aluminium oxide (Al2O3) with growing use in LED lighting and coating on the ceramic cathode separator sheets in lithium ion batteries. This paper describes a study on producing high purity alumina from feldspar to produce HPA and potash for use as a fertiliser. The project was positive for a number of reasons. High potassium extraction (>99 per cent) was achieved in the alkali leach using sodium hydroxide as the leaching agent and full dissolution of the alkali leach residue was achieved using hydrochloric and sulfuric acid. The potential to produce a high purity alumina product via a complex but promising emerging process was assessed. The potential to extract potassium as potassium sulfate to add value to the project was also demonstrated with the test work.

Sep 1, 2024