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By A Baker

Hail Creek Mine is an open cut coal operation owned by Rio Tinto. It is located 120 km south west of Mackay in the Bowen Basin region of central Queensland. Opened in late 2003, the mine produces two high quality coking coal products that are used in the production of steel in various overseas markets. Hail Creek is a dragline and truck/shovel operation with a capacity to mine eight million tonnes per annum. In 2010, the production was more than seven million tonnes.Traditionally, coal seam edge loss had been minimised on site by the practice of coal edge buffering. Importing buffer material can be quite expensive as it requires a large involvement from the truck and shovel or dozer fleet. In order to minimise this expense, a program of front splitting was introduced on site. Front splitting however involves an additional blast interaction which places added pressure on mining schedules. Both these methods of coal protection demonstrated a significant benefit with coal loss being reduced by approximately seven per cent (absolute) compared to traditional cast blasting.With the application of electronic detonators at Hail Creek the new blasting practice of dynamic buffering is able to be performed on site. Dynamic buffering refers to a blasting practice where two or three separate blasts are initiated during the same blasting event (front-split, cast and at times presplit). The process involves firing a front-split and allowing it to have time to settle and buffer the coal edge prior to the cast blast initiating. This practice is only made possible with the use of electronic detonators and the effective absence of a surface burning front. Current practice at site involves the front-split being fired (occasionally at the same time as the presplit) and the main cast blast being initiated several seconds later. Dynamic buffering is now used for all cast blasts to coal at Hail Creek. Electronic detonators have allowed Hail Creek to achieve reduced coal losses by buffering the coal edge without compromising the mining schedule.

Nov 8, 2011

By R Osterman

As mining companies have to go deeper in search of ore and coal, the importance of protecting the highwall increases. Wall fatigue also increases with importance of the long life expectancy of a highwall, in particular the impact of fatigue influenced by resonance. Resonance is the tendency of a material to oscillate with greater amplitude at certain frequencies when exposed to a periodic force. Until recently, only dominant frequencies, either natural or induced, were all that could be measured through the fast Fourier transform of the blast-induced wave form.This paper presents a novel method to accurately predict the resonant frequency of a highwall. In fact, the method can predict the natural frequencies between any two monitoring points placed in line with the source of impact, and as such it can be used to determine the resonant frequencies of any physical object. The method not only predicts the resonant frequencies of the material; it predicts the structural response of the total frequency spectrum. This method helps describe the response of a mechanical structure to excitation. It describes the structure’s efficiency in the use of energy, that is, whether energy is dampened or consumed in resonance.The initial predictions have been so accurate that it made it possible to determine the fundamental frequency and the first six harmonics of a highwall in a northern Queensland coalmine. With the use of electronic detonators, the blast can be timed with a repeating delay to create an induced artificial frequency that has been determined to retain the least amount of energy.CITATION:Osterman, R, 2015. Transfer function – new method to accurately predict resonant frequencies of a highwall, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 233–244 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By B Beamish

The concept of a ‘critical velocity zone’ in the longwall goaf environment for the development of a spontaneous combustion event has been supported by numerical modelling. However, there is no experimental data available for Australian coals to show ventilation effects on the self-heating incubation behaviour of broken coal in the longwall goaf. A preliminary study using incubation testing has been completed on three high volatile bituminous coals (A, B and C) with R70 self-heating rate values of 3.86°C/h, 3.15°C/h and 2.09°C/h and moisture contents of 11.3 per cent, 3.9 per cent and 4.7 per cent, respectively. Mass to flow rates used in the adiabatic oven reaction vessel have been selected to be indicative of a sluggish, natural air leakage and medium ventilation environment. Under a sluggish ventilation flow rate all three coals incubate to thermal runaway in minimum time frames of 2.8–3.1 years, 34–42 days and 79–95 days, respectively. When the ventilation flow rate is increased to natural air leakage, coal A with the highest R70 value and highest moisture content selfheats to 28°C above mine ambient temperature before heat loss takes over due to moisture evaporation. However, both Coals B and C at this flow rate incubate to thermal runaway in a shorter time frame than under sluggish flow. At the medium ventilation flow rate, only Coal B incubates to thermal runaway, albeit after a significant extended period of time. These results show how important it is to determine the heat balance between the coal intrinsic reactivity (as indicated by the R70 value) and moisture content. The results also have implications for the possible location of the ‘critical velocity zone’ and subsequent hotspot development and migration.

Oct 12, 2022

By M Habte

This paper presents a simplified method for the assessment of creep deformations in rock masses containing bands of low strength or soil strength rock. The main impetus for this work was the need to assess the impact of distinct bands of clay and/or low strength rock on the long term deformation behaviour of a rock pillar formed as part of a series of proposed tunnelling works. In particular, the authors were interested in being able to provide criterion which could be used by site personnel to assess the encountered rock conditions against design assumptions.Creep deformation versus time plots are presented for a range of material consistencies. These plots were produced using the hyperbolic creep equation proposed by Mesri et al (1981). This empirically based equation was chosen for its simplicity and practicality. Discussion is included regarding typical input parameter values and the sensitivity of the results to these values is explored. Finally, in the soil strength materials, the secondary consolidation equation is used to check the veracity of the results calculated using the hyperbolic creep equation.

Mar 8, 2011

By D Brereton, C J. Moran

In this era of rising focus on the social and environmental costs and benefits of mining operations, the valuation methodologies used to assess such impacts become increasingly important. Within an industry dominated by an engineering culture that places emphasis on net present value (NPV) calculations using high discount rates, difficulties often arise when attempting to justify projects with longer-term, harder to quantify benefits. This is particularly so when these benefits fall in the social and environmental domains and involve other stakeholders. In this paper, we summarise the results of a recent literature review on this subject, which focused on the valuation of æBeyond ComplianceÆ initiatives in the mining sector. We discuss a range of approaches including the quantification of hidden internal costs, financial methods of incorporating risk into calculations, the integration of quantitative and qualitative information, and also the valuation of æexternalitiesÆ or costs and benefits borne by others. We then use a series of examples relating to the management of water in the minerals industry to illustrate how some of these approaches could be applied. There are high-level commitments from both individual companies and groups such as the ICMM to incorporate sustainable development criteria into decision-making processes within the industry. We conclude the paper by arguing that, to meet these commitments, there is a need for the industry to adopt a broader range of valuation methodologies than appears to be the case at present.

Jan 1, 2006

By N S. Weerasekara, S Town, E Lessing, J A. De Torres

Philsaga Mining Corporation (Philsaga) had three main aims in converting their lining system from steel to metal cap. They wanted to increase mill availability, minimise localised high wear and optimise particle breakage to deliver increased efficiency within the milling circuit. Combining Discrete Element Method (DEM) modelling and empirical interpretation of liner wear resulted in a rigorous approach to understanding the impact of mill liners on overall mill performance. This new understanding was subsequently used to not only derive a new lining design to optimise performance and thereby improve overall plant economics, but also to guide further lining development.In this work, detailed DEM modelling, developed from actual plant data, together with optimising liner design for wear paved the way towards the installation of a Metal Cap lining system at Philsaga’s Ø6100 mm SAG Mill. The results were a reported increase in SAG mill throughput of 16 – 20 per cent due to improved breakage through more efficient use of installed power, a reduction in localised high liner wear with overall increase in liner life and reduction in liner replacement time. Site also reported an increased gold recovery of 2 per cent which the improved breakage might have contributed to. This paper will present the design challenges and compare the Metal Cap lining systems performance against Steel lining system. CITATION:Weerasekara, N S, Lessing, E, Town, S and De Torres, J A, 2018. Metal cap versus steel lining system at Philsaga Mining Corporation’s Ø6100 mm SAG mill, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 653–664 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By Carlini G, Ibba R

The KSS Lead Plant (Kivcet - SNAMPROGETTI - SAMIM) of Por tovesme, owned by Nuova Samim (the sector-head Company for non ferrous metals and derivatives owned by ENI), has been operating since february 1987. This plant is based on the Soviet Kivcet licence and testwork carried out on the pilot plant of VNIITSVETMET in Ust Kameno gorsk fed by the Nuova Samim's concentrates. The plant is com pletely automatized using the most advanced technologies and it is operated by nineteen people on shift work, including all ancillary units and lead decopperizing-casting. The expected performance of the plant has been confirmed and improves day by day in relation of the operating experience, thanks to the new conceptual design of the furnace. Due to the remarkable flexi bility of the process, the integration of the lead plant with the other plants of the metallurgical complex of Portovesme rro-#4 (Electrolytic Zinc Plant, Sulphuric Acid Plant, Imperial Smel ting) has shown all the economic advantages. The lead content in the ambient air, detected by the monitors, either in the working area and on the ground outside the complex, is widely Pb W" below the stricter new limits recommanded by the E.E.C. (Economic European Community) rules and by the Italian law. The whole process is carried out in equipment completely closed and under suction and it does not require manual operations with exposure to the lead. The production cost is much lower than that performed by the traditional technology. This advantage permits wide margin to consider investment to replace the traditional technology.

Jan 1, 1989

The constructionhunnelling industry in Hong Kong has taken an upturn during the last few years due to the commencement of works to relocate the International Airport to Chek Lap Kok Island. The Airport Core Program consists of ten individual projects including roads, landfill, bridges and tunnels to build the airport and link it to the mainland of Hong Kong. Part of one of these projects is Cheung Ching Tunnel located on Tsing Yi Island. The proposed tunnel consists of a 1.6 km twin tube road tunnel through the island's central ridge, taking three lanes of traffic each way. Each tunnel is 16 m wide - (the widest road tunnel in Hong Kong) and are 10 m high. ICI Explosives (China) saw an opportunity to supply bulk explosives to the Cheung Ching tunnel and contacted ICI Australia to determine availability of a bulk system for tunnel blasting, and assist in its introduction. This paper discusses the methodology behind developing that bulk system to suit a large tunnel drill and blast operation. It also looks at the problems encountered along the way, from the development of the product to the application of the system in the tunnel and the eventual success of introducing a bulk system into a large tunnelling project.

Jan 1, 1994

A recoverable uranium resource, shown to be suitable for in situ leaching, was discovered at Honeymoon in South Australia in 1971. Exploration of the deposit was carried out during the period from 1973 to 1979. Uranium mineralisation occurs in a coarse-grained unconsolidated sand aquifer located in the Yarramba Palaeochannel at a depth of approximately 110 m. Following initial development during 1979 to 1983 and the construction of demonstration leach facilities, the Project was put on hold. Southern Cross Resources purchased the Project in 1997. Government approval was received in March 1998 for the operation of on-site demonstration leach and recovery facilities while an Environmental Impact Statement was prepared and a 1000 tpa commercial production plant was designed. The Environmental Impact Statement (EIS) was released in June 2000 and operation of the test facility was completed in August 2000. Acceptance of the EIS by Commonwealth and South Australian state governments was announced on 20 November 2001. A Mining Lease was granted over the area of the proposed ISL operation on 8 February 2002. Operation of the Project is entirely dependent on using highly saline underground water resources to supply process and human needs. The management of discharge streams from the plant by re-injection was approved. The Honeymoon demonstration plant was the first adaptation of the solvent extraction process to highly saline in situ leach solutions. As such, it incorporated a number of unique operating and installation features. The trial period enabled optimisation of the process chemistry, additives and management and serves as an invaluable base for the proposed plant design and future operation. This paper discusses the nature of the uranium occurrence, the effect of saline water on the leach process and equipment, project design and environmental considerations, the requirements for disposal of discharge streams to minimise the impact on the arid environment and the requirements for rehabilitation following project completion.

Jan 1, 2002

By A B. Bayooke, A C. Robertson

In terms of underground tunnelling in metres advance per capita, Australasia compares well with the best world performers. This is because of the large number of metalliferous mines, coalmines and civil tunnelling projects, with the Australian tunnel advance for civil and mining projects exceeding 625?km/a. In terms of hard rock quarry extraction, Australia produces approximately 200?Mt/a of aggregates, roadbase, fill material and specialist rock products from its quarries, which equates to approximately 8?t/capita. Australian mining and tunnelling contractors are also of world standard and are used to excavating in a variable range of ground conditions in a competitive environment. One author has been involved in tunnel and underground space planning and quarrying in Australia for the past 25 years and predicts that, over the next 20 years, there will be a major swing towards underground space for commercial uses. This paper identifies the potential uses of underground commercial excavation and the planning and geotechnical challenges for the future. Underground quarrying creates new opportunities to extend existing quarries within their urban footprint with minimum impact on the surrounding community. Investigations by the authors reveal that there are very few cities in the world that actually incorporate underground space planning in their city plans. However, cities such as Helsinki have been planned in detail to utilise the rock resources beneath them. Brisbane is used as a case study for a practical application of commercial underground space and underground quarrying in Australia.CITATION:Bayooke, A B and Robertson, A C, 2014. Geotechnical challenges for underground commercial space and quarrying in Australia, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 317–322 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By L O. Filippov, A Piçarra, I V. Filippova, N P. Lima, K Silva

The reverse cationic flotation using the starch as depressor of iron oxides is the most efficient upgrading process when is applied to the simple systems composed by hematite/magnetite and quartz. The fundamental studies performed with iron ore samples from different deposits over the world (Brazil, Russia, Mexico) confirmed the inefficiency of starch when the silica content in the concentrate is controlled by Fe/Mg-bearing minerals. The main approaches for solving these issues focused on using new collector formulations or new depressants. However, the alternative depressants tested inhibited flotation of quartz or were less efficient as iron oxide depressant. In this work, a comparison between new amidoamine collector with conventionally used etheramine and oleate collectors in the flotation of pure minerals and actual iron ore samples was performed. The electrophoretic mobility, contact angle and infrared spectroscopy measurements allowed to deduce the hindrance effect as main mechanism of selective adsorption of the amidoamine on the quartz surface compared to hematite and kaolinite. Molecular modelling studies revealed that this steric hindrance effect can be explained by the combination of the "shield" formed by the coordinating water molecules on the (001)-D2 hematite surface and the large volume of the amidoamine head group. The amidoamine tested as collector without use of a depressant showed excellent flotation selectivity allowing the total flotation of quartz from a mixture with hematite. High collector performance and selectivity were confirmed during reverse flotation of quartz using continuous flotation column (D = 500 mm; H = 4000 mm) and allowed to produce the iron concentrates with more than 60 per cent of iron from the rejected slimes samples of Vargem Grande 2 processing plant (Iron Quadrangle, MG, Brazil). The new collector allowed to develop flexible flotation flow sheets to process the iron ore with a complex gangue mineralogy and unlock the old altered tailings and slimes product as new resources

Aug 24, 2022

By L Nicholls, A Parbhakar-Fox

Reprocessing Queensland’s historical copper tailings for critical minerals is an opportunity to circularise the state’s mining industry by converting waste liabilities into assets. Mine waste valorisation enables economic rehabilitation of legacy mining sites, improves environmental outcomes, and can establish a secondary resources sector that produces a sustainable supply of critical minerals to supplement growing global demands (Australian Government, 2023). The North-West Queensland Minerals Province (NWQMP) hosts numerous copper mines with known cobalt mineralisation (Degeling, 2020). Cobalt is a critical metal essential for green energy and battery technologies, however its global supply is at risk due to geopolitical and ethical concerns (Rachidi et al, 2021). Historically mining in the NWQMP has focused on copper, leaving cobalt to theoretically accumulate in the mine waste. First-pass geometallurgical characterisation of waste repositories by the Sustainable Minerals Institute identified Capricorn Copper as a key site for further investigation into cobalt deportment and recovery potential.

Aug 2, 2023

By M Astorga, J Jackson, J Gaunt

The Ban Houayxai mine (BHX) is a relatively low-grade, low-cost, open pit gold-silver deposit in Laos operated by Phu Bia Mining, a subsidiary of PanAust. The ore production rate at BHX is 4.5 Mt/a, with direct tipping to a semi-autogenous grinding/ball mill circuit with a carbon-in-leach process plant. Approximately 100 000 oz of gold is produced per annum.The operation is located in mountainous terrain with minimal run-of-mine stockpiling. This results in limited capacity for blending from stockpile, with the mill instead reliant upon direct feed ex-pit. Since commissioning in 2012, the plant has seen significant variation in milling rates due to variability in the feed properties of the oxide, transition and primary ores. As part of an ongoing continuous improvement program, an integrated approach was initiated, focusing on maintaining and enhancing production in the future as the proportion of harder primary ore increases. This will specifically focus on direct blending from the loading face using the ore properties and blast fragmentation to maintain mill throughput.This approach was based on the concept of physical assets management, commencing with improving information and knowledge of the condition of the orebody through modelling the characteristics, variability and performance of the feed for processes relevant to throughput. These models are used to support both mine and process plant production planning.The key ore feed characteristics and parameters modelled for the life-of-mine are blastability index, powder factor, crushability or impact resistance and grindability. These predictive spatial models were based on the data from diamond drill holes used in resource definition and geotechnical drilling programs by integrating geotechnical, geological, geochemical and metallurgical data.At the early stages of implementation, the models are being utilised for ore blending decisions to provide guidance and support for budgeting, long-term mine planning, blast design for mill feed and providing the mill with an expectation of performance.CITATION:Jackson, J, Gaunt, J and Astorga, M, 2014. Predicting mill ore feed variability using integrated geotechnical/geometallurgical models, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014, pp 165–176 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

By M L. Leybourne

In 2012, in response to an increasing potential unfunded liability, the Western Australian Government passed the Mining Rehabilitation Fund Act 2012. The intent of this Act was to introduce an annual levy on tenements covered under the Mining Act 1978 based on the area of disturbed land. The fund generated from these levies could then be used to rehabilitate mining sites where all other options to ensure rehabilitation had been exhausted. The fund could also be used to rehabilitate abandoned sites or features which, in Western Australia, number over 10 000.The Mining Rehabilitation Fund (MRF) was implemented on 1 July 2013 for an initial voluntary year. It becomes compulsory on 1 July 2014. By the end of March 2014, nine months into the voluntary period, over $6.5 million had been paid into the fund. The incentive for tenement holders to voluntarily enter the fund was the opportunity to have unconditional performance bonds held against their tenements retired. While there will be circumstances where bonds will continue to be applied, it is the State Government’s intention to retire most of the bonds.The MRF has received mostly accolades from industry and companies that have entered. Most have found the system easy to use. The MRF was also cited as a reason for Western Australia’s improved position in the Fraser Institute’s annual survey of mining jurisdictions. Work is now starting on processes to select priority abandoned mines for rehabilitation.This paper explains the background to the MRF and its development, and reviews its implementation during the first, voluntary, year. It also discusses how the fund will be managed into the future and what this will mean for both abandoned mine features across Western Australia and any future abandoned mine sites.CITATION:Leybourne, M L, 2014. Ensuring rehabilitation into the future – The Western Australian Mining Rehabilitation Fund, in Proceedings Life-of-Mine 2014 , pp 441–448 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By A Tsang, D La Rosa, L Julian, W Hunt, R Pratama

Mineral extraction is facing the twin challenges of finite resources and increasing environmental and economic costs. Society’s growth is matched by an increase in demand for the earth’s resources. It is incumbent on us as contemporary mining professionals to promote and facilitate ethical and efficient practices. Technological developments have and will continue to allow a decrease in viable cut-off grades, creating new economic opportunities from deposits that were previously uneconomic. Mining low-grade deposits however, even with perfect recoveries, will have a significant environmental cost for the metal won. The greatest opportunity to increase metal with the least environmental cost is to increase the metal yield from existing mines. The determination of mining polygons is a critical juncture where rock is typically subjected to the binary grading of either ore or waste. This is undertaken using a number of factors, such as the mining equipment being used and the recovery in the processing plant. Traditionally, mining polygons were generated on the in situ grade control model. This ignores the complex differential blast dynamics that occur during blasting. Two opportunities exist to improve metal yields: optimise the blast design to achieve the post-blast muck pile that will support the greatest outcome; and generate optimised polygons on the post-blast muck pile. A data set from a Canadian Gold deposit is used to demonstrate the potential benefit of iterative blast movement modelling and grade control polygon optimisation on metal yield. The impact of blasting on the total recoverable metal is presented, highlighting blast design as a critical process in the mining value chain.

Sep 1, 2024

By Mitchell I, Gelfi P, Dunne R, Pyper R

Dump leaching at Teller in its present form began in the fourth quarter of 1988 as an adjunct to milling operations. Initial plans called for a dedicated dump leach facility capable of processing ore at an annual rate of 2.0 million tonnes. Construction of a dump leach pad, collection and process ponds, carbon adsorption system, elution plant as well as reagent addition and ancillary facilities was initiated in mid-1988. During the course of construction, additional reserves were proven. As a result, design throughput was increased to 4.0 Mtpa. Leach pad capacity and solution supply systems were upgraded to handle the larger throughput. However, the carbon adsorption/elution facilities were not upgraded due to space limitations. During 1990 it was decided to expand the dump leach operation to 6.0 Mtpa. Construction of a second leach pad was required which was initiated in early-1991. Plans were again upgraded prior to completion to a target annual throughput of 10.0 million tonnes was. A further two leach pads have been constructed. The first of these being completed during the latter part of 1992. Construction of the latest and largest pad commenced early in 1994.

Jan 1, 1994

By S Goff

The Northern Sewerage Project (NSP) is a $650 M infrastructure project that will increase the capacity of the sewerage system for Melbourne’s growing northern suburbs while also helping to protect the Merri and Moonee Ponds creeks by significantly reducing the number of sewage overflows that can occur after heavy rainfall. The NSP consists of two stages: Stage 1 (NSP1) will be owned and operated by Melbourne Water Corporation, and Stage 2 (NSP2) will be owned by Yarra Valley Water and operated by Melbourne Water Corporation.Glass-fibre reinforced plastic (GRP) was used on both NSP stages, however, since Stage 1’s schedule for installation of GRP was slightly ahead of Stage 2’s, this paper will only focus on Stage 1’s use of GRP.NSP1 involves the construction of 7.9 km of new sewer tunnel ranging in diameter from 1.6 to 2.5 m, five main access shafts at depths of up to 65 m, and connections to the existing sewerage system including several access manholes. Construction began in 2007, and project completion is expected in 2012.The original design for NSP1 specified the use of high-density polyethylene (HDPE-) line precast concrete pipes as the final tunnel lining and HDPE-lined reinforced concrete for the access shafts and manholes. During construction, the rising cost of precast concrete pipes and the introduction of an additional GRP pipe supplier in the market justified a review of the tunnel final lining material. The contractor-proposed GRP pipe alternative was accepted for the final tunnel lining based on time and cost savings that were possible without compromising the design intent. After gaining experience with GRP through this design change, Melbourne Water Corporation reviewed and accepted GRP as the final lining for five smaller connection manholes. The use of GRP for the manholes was particularly inventive as the redesign made use of the approved tunnel GRP pipes as both a structural and corrosion-resistant lining.This paper discusses the use of GRP on NSP1; how the change in material, from concrete to GRP, affected the design philosophies assumed during detailed design; and how construction methods were modified to handle the less rigid GRP material. Details on the structural, hydraulic and durability considerations for the design are included, as are details about the time and cost savings and the quality and safety improvements that were achieved during construction.

Mar 8, 2011

By T Ireland

The Rosedale Outfall Project utilised an earth pressure balance (EPB) tunnel boring machine (TBM) for only the second time in Auckland. Although the tunnel was excavated fully through East Coast Bays Formation (ECBF), the downhill gradient along with some unexpected areas of extreme water posed some significant challenges during construction.The Rosedale Waste Water Treatment Plant Outfall Tunnel project was commissioned in response to the growing needs of North Shore City, New Zealand. The outfall tunnel comprises a 3 km long segmentally lined tunnel and a 2.1 km buried marine pipeline, and discharges 2.7 km offshore. The capacity of the new outfall is 6 m3/s compared to the existing outfall capacity of 1 m3/s.Following previous project experience, and with the tunnel located along its full length in the bedrock weak sandstone/siltstone bedrock of the East Coast Bays Formation, tunnelling conditions were expected to be benign. However during construction six high inflow events were encountered, including a full face (3.4 m diameter) of Albany Conglomerate over a 48 m length of tunnel. This material comprised cobbles in an uncemented sand matrix, and inflows were recorded at over 25 L/s.This paper describes the design challenges on the project including the design of a steel fibre reinforced segmental lining for internal pressures. The specification of the machine is discussed including the modifications required to enhance the risk mitigation measures already in place. The ground conditions encountered are discussed and have improved the knowledge of the range of conditions that can be expected in Auckland.Despite the challenges presented during construction, excellent progress rates were achieved and the tunnelling was successfully completed ahead of program.

Mar 8, 2011

By S Oliver, D Willingham

"Although a resource model is central to the mineral resource value estimation process (Glacken and Snowden, 2001), creating it is a labour intensive task and in the end it is a limited representation of the actual orebody. Creating this resource model is a labour intensive task that requires inputs from geology, mining, metallurgical and commercial disciplines. It requires thousands of samples from hundreds of drill holes to be verified, grouped in geological domain, interpolated and then valued. Even after all this effort, a model is only an estimation; therefore further significant effort has gone into quantifying uncertainty in the model and subsequently risk around any value estimates derived from the model. Further risks to model quality are introduced through poorly conditioned data or incorrect assumptions.This paper proposes the application of machine learning to automate the resource model development. Machine learning is applied to the traditionally manual tasks of geological formation, domain identification and validation of the block model mineralogy. Through automation the resource estimation process can be accelerated, allowing more drill holes or a larger resource body to be processed in a given time frame, or allowing the process to be more agile to changes in input data and assumptions. A case study based on drill hole data from a Western Australian iron ore deposit (Government of Western Australia, Department of Mines and Petroleum, 2015) is used to demonstrate the application of machine learning in this process.CITATION:Oliver, S and Willingham, D, 2016. Maximise Orebody Value through the Automation of Resource Model Development Using Machine Learning, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 295–302 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By W. M. LONIE

Address by the President of the Institute (Mr W M Lonie) in making the presentation of the Certificate of Honorary Membership to Sir Ian McLellan, K.C.G.M, K.B.E. Address by Sir Ian McLellan after accepting the award.

Jan 1, 1979