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By Bruington T, Perkins J, Hutton R

Natural resource developments are among the largest and most challenging projects taking place in the world. They involve capital intensive investment with long lead times and the management of geological, market, technical, operational and financial issues. A clear strategy is required to manage these projects and this strategy is underpinned by a development Philosophy.

Jan 1, 1997

By J Siliézar

The Ernest Henry Mine (EHM) is situated 38 km north-east of Cloncurry in the Mount Isa – Cloncurry mineral district of northwest Queensland. The EHM orebody is an iron oxide copper gold deposit with an average grade of one per cent copper, 0.5 g/t gold and 23 per cent magnetite, with current reserves of approximately 88 Mt.The copper concentrator is a single line plant with a nominal throughput rate of 1300 tonnes per hour. An average of 350 000 tonnes of concentrate is produced each year containing around 100 000 tonnes of copper metal and 120 000 troy ounces of gold.In December 2009, Xstrata Copper announced approval of a $589 M investment to extend the life of EHM to at least 2024, through the transformation of open pit mining operations to a major underground mine together with the construction of an associated magnetite extraction plant.The EHM magnetite plant extracts the magnetite from the copper concentrator’s tailings stream. It will produce approximately 1.2 Mt of magnetite concentrate per annum at full capacity for export to Asia, making EHM Queensland’s first iron ore concentrate exporter. Construction of the magnetite extraction plant commenced in July 2010 and was completed in January 2011.This paper gives an overview of the development of the EHM magnetite extraction plant flow sheet from the early mineralogy and laboratory test work through to the plant commissioning and early operation of the base plant. It has a major focus on the commissioning learnings from the plant start-up and includes a review of the operational performance of the plant versus original design and expectations.

Jul 11, 2011

By Zharinov SE

Geonechanical modelling of island arc sys- tems and their analogs is investigated. Slow seismotectonic movements along the inclined deep fault zone under the compressive horizontal stress conditions are proposed to be the princi- pal mechanism controlling the structures and processes in the active continental margins. A model of shearing surface crack in an elastic half-plane is used for simulation. The main ele- ment of the model is viscous interaction bet- ween the crack sides, the viscosity varying with depth. To describe the stress-strain state of the medium an integro-differential singular equation is derived and solved numerically. The results of simulation are in good agreement with geological and geophysical data on the ac- tive continental margins.

Jan 1, 1987

By Tilley H. L

The 90 m deep Yallourn Open Cut brown coal mine in the Latrobe Valley, Victoria is developing into an area close to a reverse fault. A major batter stabilisation program, matched to ongoing operations, has com- menced to maximise coal recovery where the fault is within 100 m of the Open Cut. The various mine development options considered during the planning stages are outlined. These options were formulated in a back- ground of geotechnical constraints and the need to maintain continuous and reliable coal supply at a time when a new coal field would be developed. The geotechnical investigations and analysis procedures under- taken to determine stability of the batters during their excavation are presented. The geotechnical constraints on the mine design and opera- tions required to ensure safe working conditions are detailed. Current operational and batter stability conditions are considered satisfactory.

Jan 1, 1989

In late 1984, Council of the Australasian Institute of Mining and Metallurgy accepted a proposal to establish a Mineral Heritage Committee. This was to be involved in matters relating to mineral heritage-its recording, its preservation, and the acknowledgement that it can be of use to the mineral industry in the future. The Committee was established to ensure that all of the disciplines of our profession were included and that, so far as possible, all of our country as well as those countries of the Southwest Pacific Basin were represented. Some work has been commenced to bring real- isation of the importance of the heritage of our mineral industry to the forefront of the commu- nity's interest. There is not a state in this country and the Southwest Pacific where the mineral industry has not at various times proved to be the basis of community development.

Jan 1, 1987

By V Yadi

Geostatistics has been widely used for more than four decades as a powerful tool in ore resource/reserve estimates and grade control. This method has gradually replaced the conventional method such as polygon and cross-section for grade estimation by more mathematical techniques such as kriging. The advances in geostatistical understanding and the availability of appropriate software packages have given much more contribution in speed and high accuracy during production. However, in many cases, these techniques are sometime applied without support with a good thorough understanding of the geological controls on metal distribution. To produce the result close to actual, the geological control in interpretation and appropriate geostatistical task is a must. Geological logging was described in the core must be consistent with the level plan produced by commercial modelling software used as a guide for grade control during production. Experience gained through evaluation of the Central I deposit resulted that the most effective systems continue to be based on geostatistical methods of resource estimation. Computer applications modelling software packages are necessarily as the core of an efficient in undertaking these assignments. They contribute to make a valued to data management and are becoming increasingly effective during processing. The latter role is particularly important to check the actual versus estimated values where will significantly to improve personnel to have a confident with their knowledge combined with experience and complete their jobs satisfy.

Aug 22, 2011

By T Peglas, A de Aboitiz

The Queensland Government, via the special purpose company vehicle û City North Infrastructure Pty Ltd û is currently developing BrisbaneÆs Airport Link underground toll road and Northern Busway (Windsor to Kedron).Airport Link is a predominantly underground toll road planned between BrisbaneÆs northern suburbs, the airport and the Brisbane Central Business District (CBD) frame. The Northern Busway forms part of BrisbaneÆs expanding busway network, sections of which will be jointly delivered with Airport Link. Airport Link will connect the North-South Bypass Tunnel, Inner City Bypass and local road network at Bowen Hills to the northern arterials of Gympie Road and Stafford Road at Kedron and Sandgate Road and the East-West Arterial in the cityÆs north-east. The Northern Busway is a two-lane, two-way bus-only roadway proposed to connect the existing Inner Northern Busway at Herston with Windsor, Lutwyche, Kedron, Chermside, Aspley and Bracken Ridge. Airport Link and Northern Busway (Windsor to Kedron) is one of the largest infrastructure projects planned in the first phase of the State GovernmentÆs South East Queensland Infrastructure Plan and Program. The paper will provide an overview of the projects, including a discussion on the technical and environmental aspects as well as the procurement of the Airport Link as a public private partnership.

Jan 1, 2008

This paper describes operational experience with seam gas and spontaneous combustion management, gained during ten years of production history (1993 to 2003) in the Wynn seam at Dartbrook Coal mine. In addition, comparisons are made with more recent operational experience in the overlying Kayuga seam. Development and retreat longwall operations were undertaken in a 4.0 m thick working section of the Wynn seam, contained within the lower quarter of a circa 24 m thick mega seam, from 1993 until mining operations were relocated to the overlying Kayuga seam in 2004. Production from the first block of the Kayuga seam is currently underway with seam gas and spontaneous combustion management requirements being refined as further operational experience is gained. Seam gas management techniques, including pre-drainage with pressurised fracturing, surface to underground goaf drainage of a carbon dioxide rich seam gas and novel, high capacity ventilation circuits, were employed in the Wynn seam. Ventilation strategies included operating up to carbon dioxide STEL concentrations of 3.0 per cent in segregated return airways rather than being limited to the TWA-TLV concentration of 1.25 per cent. The spontaneous combustion experience at Dartbrook Coal has, to some degree, resulted in a change in the way the risk is managed in Australian coal mines. Values of carbon monoxide make and hydrogen concentrations are profoundly different from previously recommended management plan trigger levels and those used elsewhere in the industry. However, the detection of higher hydrocarbons together with rising oxygen depletion ratios and absolute hydrogen concentrations remain as indicators of advancing spontaneous combustion events. In this respect, experience gained in the Wynn seam was important in the initial management of the shallower Kayuga seam, an essentially greenfield site with no prior operational experience being available.

Jan 1, 2005

By Hughes CA

The need to recover metals from low grade deposits, old tailings, etc., combined with improvements in equipment design and the development of new extractants, has resulted in solvent extraction (SX) metal recovery reaching new importance (Webster & Ferron, 1993). The basic principle of solvent extraction is the use of an equilibrium system in which a metal ion is transferred from an aqueous phase into an organic phase, (Equation 1), (Ritcey, 1984). M + E ME . (1) The organic extractant (E) is usually specific for a certain metal ion (M) and forms a metal complex in the organic phase, leaving the impurities behind in the aqueous phase. To recover the metal, the equilibrium is reversed and the metal ion is transferred back from the organic to another aqueous phase in a process called stripping. The metal is then recovered from the aqueous strip solution, usually by electrowinning.

Jan 1, 1990

By Toivanen R-M, Leinonen O, Pekkarinen H

This paper presents developments in designing an integrated mine control system at Kemi mine. The aim of this paper is to present the general structure of the system and to outline some features of the process control strategies. The results o

Jan 1, 1998

By A Mehrani, F Zamani, A Dehghani

Vibrating screens play an important role in the dry classification circuit of Gol-e-Gohar iron ore processing plant. This circuit was designed to classify the autogenous mill discharge and produce a suitable feed, with K80 about 450 ¦m, for dry magnetic separators. Three parallel vibrating screens produce more than 50 per cent of the separatorÆs feed. The efficiency of the magnetic separator is greatly affected by feed size distribution. In this work, the JKSimMet 5.1 software was used as an analysing tool to assess the flow rates and USIM PAC3 software as the simulation tool to control and optimise the vibrating screens. Samples were collected and the circuit was mass balanced. Then the vibrating screen was simulated and adjustment parameters such as cut-point, bypass and imperfection factor were determined. The product streams of vibrating screens can also be predicted.

Jan 1, 2007

By Bure R

Approximately 2.4 million ounces of gold and 11.3 million ounces of silver have been produced from the Umuna Lode by Misima Mines Pty Limited between June 1989 and the end of Decemeber 1996. Reserves remaining at the end of December were 32.1 million tonnes at 1.0 gram per tonne gold and 9.7 grams per tonne silver. To attain precious metal production of this volume, an estimated K60,000,000 (1996 Kina) was spent on exploration alone. from the 1940s to the present day. Exploration expenditure for the 1996 calendar year was approximately K4,400,000. With such a large investment in exploration, large quantities of data were generated and stored in various forms. To make best use of this data, it was necessary to organise and systematically store this data in a form compatible with a modern Geographical Information System (GIS). The Umuna Lode on Misima Island is a low sulphidation gold- silver deposit dated at 3.5 ¦ 0.2 Ma. The deposit is controlled by the 50 to 100 metre wide Umuna Fault- a moderate dipping, brecciated clay- chlorite- carbonate altered, normal fault zone. There is approximately 230 metres of mostly dip slip offset on this fault, which is measurable by the offset of the Cretaceous schist, marble and greenstone host sequence. Late Miocene microdiorite spatially related to the Umuna Lode does not appear to be genetically related to the gold- silver mineralisation. GIS was introduced to Misima at the end of 1995 and until recently has been mostly used for data storage and retrieval, the over- laying of various data sets to assist in targeting prospective areas, and as a drafting tool. The use of data-driven, predictive data analysis is the most recent effort in maximising the use of the extensive Misima database. By characterising the key controls and properties of the Umuna- type mineralisation, a Weights of Evidence, data-driven analysis produced a prospectivity map of Misima Island. The purpose of this map was to identify prospective areas yet to be explored and to assess the effectiveness of exploration to date.

Jan 1, 1997

By Bigu J, Grenier M. G, Knight G

Particulate control is a major concern in underground mining and the subject of continuing research world wide. In Canada the federal government's Mining Research Laboratory at EIIiot Lake, Ontario, has been using two aerosol counters to aid its investigations. Specific studies with the units include: a) evaluating total and elemental size efficiencies of dust filtration units: b) characterizing the dust particulate cloud from different mining operations: and c) determining dust transportation characteristics.

Jan 1, 1988

By T Barto, D Thomson, T Norgate, C Doblin

Collaboration between CSIRO Minerals and SunSalt Pty Ltd, a salt producing company located in rural Victoria, has resulted in a commercial process to recover magnesium sulfate (commonly called Epsom salt) from the saline waters of the Murray Basin. The feed for this process is bittern; the liquor remaining after halite (common salt) has been harvested from the saline water by evaporation.SunSalt produces salt and bitterns from three locations, namely Hattah (Victoria), Mourquong (NSW) and Wakool (NSW). The small size and considerable distances between these operations makes it uneconomic to build a stationary processing plant to extract value-added products, in particular Epsom salt, from the bitterns of the three operations. This fact led SunSalt to build a containerised mobile plant that could be moved to each site to process the bitterns at the end of the salt harvesting period.Epsom salt is extracted from the bittern by further evaporation, refrigeration and recrystallisation. In this process the bittern is diluted with five per cent volume of fresh water to minimise precipitation of residual halite in the bittern. Cooling the diluted bittern to between -5 and -10¦C precipitates up to 70 per cent of the magnesium sulfate, which is recovered as 85 to 96 per cent purity Epsom salt by filtration. This product is marketed as an industrial grade Epsom salt. Higher purity (up to 99.9 per cent) Epsom salt (USP or BP grade refined product) is made from the industrial grade product (raw Epsom salt) by recrystallisation.The containerised mobile plant was commissioned in December 2002. The raw Epsom salt generated in the mobile plant is refined to a higher purity Epsom salt in a separate plant located in Mildura. The Mildura plant was commissioned in December 2003.The CSIRO-SunSalt collaboration has demonstrated that the saline waters can be processed into a useful resource, and in addition could create jobs and a new skill base in regional Australia. The production of Epsom salt locally in Australia, which is worth currently about $A600 per tonne, removes the need to import over 3000 tpa from overseas with a net positive impact of $A2 million on the balance of trade.

Jan 1, 2004

By M Behrens, A McPhee, B D. Hegan

This paper describes the design and construction of twin 400 m long road tunnels as part of the Northern Motorway Extension Project in Auckland, New Zealand. Construction of the tunnel civil works is now completed and installation of mechanical and electrical systems is well underway. The tunnels are expected to be open for traffic at the end of 2008. The paper will address the design aspects of the project including: tunnel alignment and cross-section, geotechnical conditions and rock support, waterproofing and concrete lining and fire and life safety. The paper will cover the bored tunnel section, the cut-and-cover tunnel section, cross passages and portal structures. The design brief included a requirement for the tunnels to be a gateway to Auckland and this required particular attention to be given to the visual appearance of the finished tunnel structure. The final arrangement of the portal structures and a requirement for recesses in the concrete lining for emergency cabinets, deluge pipework and cable runs, reflects these requirements. The tunnels were excavated by a roadheader and road planer using a heading and bench. Initial support was provided by a combination of lattice girders, cement grouted rock bolts and steel fibre reinforced shotcrete. The permanent lining consisted of installation of a drainage geotextile and waterproof membrane, followed by cast in situ unreinforced concrete. Each portal consists of a cut-and-cover section. This paper describes the tunnel construction methods, including the particular requirements for safety, the environment and community relations. The tunnel is fitted with a compartmentalised deluge system for fire fighting purposes. The tunnel control centre is incorporated into the control centre for Auckland Harbour Bridge, some 30 km from the tunnel location.

Jan 1, 2008

By Hayward N, Sutherland D, Wilkie G

A pilot plant study has been made of the liberation characteristics of a nickel ore under different milling conditions. A series of runs were made ranging from fully autogenous grinding to semi-autogenous grinding with a ball load of 8%. The mill products were sized and assayed then analysed by QEM4SEM. This enabled a full liberation analysis to be carried out to see whether the autogenous grinding leads to improved liberation by promoting selective breakage. Though it is frequently claimed that fully autogenous grinding yields superior liberation this could not be detected in the present study.

Jan 1, 1991

By Abrahamsson S, Niklasson B

In a follow-up of 12 production blasts in a quarry at the Mrica project on Java, tightly spaced porous bands were found to govern fragmentation to the extent that the average fragment size k5o was nearly independent of the specific charge within the range 0.30-0.56 kghn3. This fording resulted in a reduction of the running costs for drilling and blasting by 20-40%. Our work has given considerable practical benefits and insights into the blasting process, even if the results were of no direct use to check out fragmentation predictions based on models, which was one of our main Goals.

Jan 1, 1990

The Jurassic Walloon Coal Measures crop out over much of the Moreton Basin and contain numerous thin, banded coal seams which have been mined at various locations since the 1870s. Historically most mining has been by underground methods. Increased exploration during the 1970s and 1980s has led to the delineation of significant open cut coal resources and to the development of the Oakleigh, Jeebropillly and Ebenezer open cut coal mines in the Rosewood-Walloon area. Over 2 170 million tonnes in-situ of shallow, high volatile bituminous coal with a mean maximum vitrinite reflectance of between 0.5 and 0.6 have been proven in the Basin.

Jan 1, 1991

By Best R. J, Poulos H. G

The method for design of primary roof support for the large todoidal cavern constructed to house the Sydney Opera House parking station is presented. The cavern was constructed with 5 m of rock cover beneath Sydney's Royal Botanic Gardens. Design of rock reinfonnent using a combination of fully grouted rock dowels and Macalloy bars was based on control of horizontal shear movement along bedding features in the roof. A combination of linear arch type analyses and non-linear jointed finite element analyses were used in the design study together with an analysis of the shear resistance offered by fully grouted bolts under shear deformation.

Jan 1, 1993

By Leahy GJ, Wright DJ, Player RI

The operation of a one tonne submerged combustion pilot plant for the recovery of copper from anode furnace and converter slags is described and the effects of variables discussed. Using coal as reductant, copper levels of anode furnace slag were lowered to 1% or less, with batch times of approximately 120 minutes. Fluxing with limestone was required to produce a fluid slag at temperatures of 1200 - 1300¦C. For converter slags, reduction to 0.5% Cu or less was achieved in batch times of 35 minutes. The chemistry of the pyrometallurg- ical recovery of copper is briefly reviewed in relation.to copper recovery methods.

Jan 1, 1978