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By B Roache

Ground support installation into the face of development headings has become an accepted practice at many Australian hard rock mines. Ground support is installed in the development face to reduce personnel exposure to rockfall while conducting work tasks such as marking up, installing lifter tubes, charging, and face sampling. The ground support system installed in the face is typically friction bolts and mesh. This support system can be effective at reducing rockfall occurrence, but it also increases the cost of development per metre, in terms of capital for the ground support, jumbo and operator capital allocation and the installation time slowing each drill and blast cycle. Other issues associated with meshing and bolting the development face include management of rock bolts and mesh sheets in the fired dirt of every cut, damage to services such as vent duct, geometry issues when installing ground support onto irregular development profiles and operator error. Fibrecrete installation onto the development face for support is an option considered by many mines, but it can be difficult to manage due to the removal of visual indications of misfires and slowing the mining cycle due to the wait time for fibrecrete curing. The use of Thin Spray Liner (TSL) products in underground hard rock mines has been relatively infrequent in the past, mainly due to issues with cost, health and safety, and liner strength. Kanmantoo Mine investigated the use of TSLs for the purpose of development face support, while collecting data on the costs and practicalities associated with their use. Several TSL products were trialled and a preferred TSL product was selected for use as face support. Cost savings, drill and blast cycle timing improvements and other benefits were achieved while meeting the requirement to reduce rockfall risk.

Mar 29, 2023

By M Watts, P Lindsay

Herbert Stream, a tributary of the Waimangaroa River on the Stockton Plateau, has elevated metal concentrations and low pH characteristic of acid mine drainage (AMD). Dissolved aluminium concentrations average 8.3 ppm, iron 1.4 ppm, manganese 0.69 ppm, and zinc 0.12 ppm and pH ranges from 2.8 to 3.2. Flow rates range from 2.3 to 26.6 L/s with an average of 5.3 L/s. To determine the effectiveness of different treatment strategies, a small amount of the AMD was diverted through three small-scale passive AMD remediation systems over an eight month period. These included a reducing and alkalinity producing system (RAPS), a limestone leaching bed (LLB), and an open limestone channel (OLC). Both the RAPS and the LLB performed well, effectively removing metals and restoring pH. The RAPS lowered aluminium concentrations by up to 99%, iron 97%, manganese 95%, and zinc 80% and the LLB lowered aluminium concentrations by up to 99%, iron 99%, manganese 92%, and zinc 91%. The pH was restored to between 6.4 and 7.4 by the RAPS and to between 7.3 and 7.9 by the LLB. The OLC performed well as long as the residence time was similar to that of the other treatment systems. OLC removal rates for aluminium was up to 99%, iron 94%, and manganese 21%, and the pH was restored up to 5.6. Due to its simplicity and effectiveness, it is proposed the LLB be constructed to fullscale size to treat the entire Herbert Stream.

Jan 1, 2007

Many types of micro-organisms inhabit iron ore deposits contributing to biogenic formation and conversion of iron oxides and associated minerals. Bacteria such as Paenibacillus polymyxa are capable of significantly altering the surface chemical behaviour of iron ore minerals such as haematite, alumina, calcite and silica. Differing mineral surface affinities of bacterial cells and metabolic products such as proteins and polysaccharides can be utilised to induce their flotation or flocculation. Mineral-specific bioreagents such as proteins are generated when bacteria are grown in the presence of haematite, alumina, calcite and silica. Alumina-grown bacterial cells and proteins separated from such cells were found to be capable of separating alumina from haematite. Biodegradation of iron ore flotation collectors such as amines and oleates can be effectively utilised to achieve environmental control in iron ore processing mills.

Jan 1, 2009

By R Carreau

The results of a detailed acid rock drainage (ARD) prediction program were used to revise the waste rock segregation criteria at the Restigouche open pit mine. Waste rock at the site was predominately derived from altered volcanic rocks that hosted a massive sulfide lead/zinc orebody. The program assessed the five years of drainage chemistry from both the potentially acid generating and the non-acid generating waste rock storage facilities in addition to laboratory-based kinetic test results. Material-specific leaching characteristics including relative metal-release rates and neutralisation potential depletion rates were determined from 12 laboratory-based kinetic tests. Solid-phase analyses indicated that, although pyrite was typically the most abundant sulfide mineral in the waste rock, its abundance varied significantly as documented by total sulfur contents ranging from 4.0 per cent. Kinetic test results were used to establish revised waste rock segregation criteria based on total sulfur content and neutralisation potential. The revised criteria maintain that waste material with a total sulfur content 4.0 per cent as potentially acid generating. When present in sufficient quantities, ankerite provided an effective source of neutralisation potential for the range of observed sulfide oxidation rates. Kinetic testing documented that up to 6 kg CaCO3/t was ineffective at neutralising acidity in samples that contained >4 per cent S. The carbonate molar ratio measured from the humidity cells was adjusted to reflect the stoichiometry of the ankerite and applied as an NP/AP criteria for waste rock containing 0.1 <S per cent <4.0.

Jan 1, 2003

By A C. Robertson

World urban expansion puts constraints on the available land surface area of our major cities both for accommodating people as well as providing infrastructure and services whilst at the same time attempting to preserve the remaining natural environment. Whilst consideration is often given to underground planning for private and public transport infrastructure, the author is of the opinion that the current lack of underground planning of our cities that are suitable for underground development will have major long implications when finally the need for underground space planning is critical and ultimately recognised. This paper identifies the need for our city planners to integrate surface planning and underground planning as a ‘total planning solution’ where the city plan incorporates the elements of underground space planning as identified in this paper. Investigations by the author reveal that there are very few cities in the world that actually incorporate underground space planning in their city plans. The author uses the City of Brisbane as a case study for the potential introduction of underground space planning as part of the city plan. Despite efforts by the author to include the planning concept of underground commercial development in the latest Brisbane City Plan 2014 as well as four underground space workshops in Brisbane over the past 20 year through the Australasian Tunnelling Society (ATS), underground space planning for the City of Brisbane, apart from infrastructure projects, is not considered of significance to the City of Brisbane.CITATION:Robertson, A C, 2014. Commercial underground space – planned development for the future, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 513–518 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By M P. Sandy, J B. Albrecht

"Narrow vein mining can be loosely defined as mining operations involving orebodies with a true thickness of less than 4 m. Some authors have limited the term to steeper-dipping orebodies where the ore will rill under gravity. However, ænarrow veinÆ can also legitimately refer to some of the flatter orebodies, such as many of the platinum, chrome and gold deposits of Southern Africa, and several in Australasia including Bullen (at Norseman), Sunrise Dam, Telfer (Patterson, 1993) and the famous æflatmakesÆ at the Emperor Gold Mine in Fiji (Gordon and Harmse, 1993). Where the orebody dip is less than about 40¦ additional effort is usually required to remove the broken ore, including the use of scrapers, hydraulic monitors or remote-operated excavators (Tombs, Buckingham and Hancock, 2008).Working in such narrow orebodies presents particular operational and geomechanics challenges. A range of mining methods have been developed or adapted to exploit narrow orebodies including:cut-and-fill,narrow vein bench or longhole stoping,Alimak stoping,shrinkage stoping, and methods for shallow dipping orebodies (including Airleg and mechanised methods).The paper discusses some of the advantages and disadvantages of each method with a focus on geotechnical aspects including mining sequence options, stress management, ground support requirements, dilution and recovery.CITATION:Sandy, M P and Albrecht, J B, 2012. An overview of geotechnical issues in narrow vein mining, in Proceedings Narrow Vein Mining 2012 , pp 185-194 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 26, 2012

By G Senanayake, K Hazarika

The demand for iron-ore is ever increasing with the industry directly employing 60 500 people in a range of highly skilled roles in Australia. In the year 2019, the global iron-ore production was 2.85 billion tonnes. It is estimated that each tonne of beneficiated iron ore produces 400 kg of tailings. The IOTs are fine, dense and stable crystalline material mainly composed of iron oxides, alumina and silica. The current and most applied method of iron-ore tailings (IOTs) disposal is using subaqueous disposal of tailings in dams. The footprint generated by a tailings dam is massive and requires constant monitoring due to the possibility of a failure making the operation and maintenance of tailings dam extremely expensive. This review briefly discusses the known causes of tailings dam failures, their impact to the environment and day-to-day human life and potential applications of IOTs. The increase in water content enhances the pressure on dam walls. This in turn increases the liquefaction potential of the tailings and reduces the overall strength of the dam making it more vulnerable to failure. Potential applications of IOTs are in paints, aggregates in construction materials and bricks. The reuse of IOTs reduce waste and generates further revenue facilitating a path towards a sustainable future for the industry.

Nov 8, 2021

By C Tickell

Achieving occupational health and environmental noise objectives is a major consideration in the planning or operational phase of resource development and industrial projects to meet the needs of the workforce and community and comply with legislative requirements. For material handling systems, ventilation plants, mobile equipment, process plants and fixed infrastructure, noise emissions need to be considered at the design phase. The preferred approach is to provide noise emission technical specifications, but in many cases this is not stipulated. An occupational noise requirement, such as ‘not to exceed 85 dBA at 1 m’, is often provided, but this will not achieve the required occupational or environmental noise objectives and may cause overly stringent requirements when they may not be needed. It should be noted that when developing the technical specification, measuring compliance needs to be taken into account as, in some cases, measuring may be very difficult or even not possible.This paper will discuss the requirements for providing an effective noise specification that ensures the environmental and occupational noise objectives are able to be achieved and that, once installed, compliance can be measured. It discusses planning such as when to set the objective, correlating the appropriate objectives for the environmental and occupational noise requirements, allowing for measurement tolerance, providing a suitable criteria and data format for the suppliers to respond to and methodology to measure compliance. Different phases of a project require different approaches to planning for noise management and these will be discussed in the paper. Examples from 35 years of industry experience will be included.CITATION:Tickell, C, 2016. Preparing effective specifications for occupational health and environmental noise objectives in mining project design and delivery, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 781–788 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By E Niva

The IsaMillÖ is challenging the way that plants are designed and operated. This paper challenges existing designs of concentrator flow sheets, particularly focusing on magnetite circuits.   From what has started out as a small scale ultra fine grinding mill in the pharmaceutical and pigment industries, it has been redesigned and improved upon for mineral processing, and has been the mainstay of fine grinding applications for over ten years. These applications have required energy efficient grinding to succeed, and have been predominately in the base metals industry.   Further development of the IsaMillÖ has now resulted in the machines being able to treat larger tonnages, with higher capacity motors. This development, along with the introduction of purpose designed ceramic media, has allowed the mill to treat courser feed sizes. At the same time, the mill still offers highly efficient grinding, and has enabled it to be operated in coarser tertiary and secondary grinding applications.   The acceptance of the mill in coarser applications, predominately in base metals and PGM applications, has enabled the IsaMillÖ to be a serious contender for beneficiation in other minerals. One such application is the potential for IsaMillsÖ to be part of magnetite flow sheets, which are being considered in Australia to meet the growing iron demand of China. The high energy efficiency of the IsaMillÖ compared to conventional technologies, as well as the smaller infrastructure requirements, provides a great opportunity to reduce the power intensity of magnetite circuits.   This paper will examine the use of IsaMillÖ technology in conventional grinding applications, including recent testwork in a primary grinding base metal circuit, as well as testwork on magnetite ore comparing a lab scale IsaMillÖ with a lab scale Tower Mill.   The growing demand for minerals over the next decade, coupled with higher energy cost, will result in energy efficient technology, such as the IsaMillÖ, being included in standard circuit design.

Jan 1, 2008

Xstrata CopperÆs Mount Isa Copper Operations is located in mineral rich north-west Queensland and is one of the largest sources of copper in the world. This world-class underground operation is planned to produce over 6.6 million tonnes of copper ore in 2007 from the X41 and Enterprise Mines. With an underground mining history of over 50 years and underground reserves of over 83 million tonnes at 2.6 per cent copper, mine planning for the future becomes an exciting challenge for the technical team due to the older nature of certain areas. The 1100 Orebody of the X41 mine was one of the first places that copper mining occurred, with its discovery in 1953 - 1954 and mining commencing in the 1960s. Sublevel open stoping mining methods have been employed since that time as the means of extraction, using a primary-secondary sequence to maximise stope turnaround time. Large Transverse Pillars within the 1100 orebody were not mined out in order to provide access for ventilation, power, orepasses and other services. The Panel Pillar, 4180XC and 4010XC pillars are three such Transverse Pillars in the 1100 orebody that will be mined as a final retreat. This paper discusses the technical challenges and issues associated with the extraction of Q390 stope, one of the stopes located in the Panel Pillar, and the design solutions to overcome these issues. Managing the exposure of backfilled stopes of variable fill strength, ensuring the stability of the crown, stope walls and drawpoints, managing vertical openings, re-establishing service networks, and stope filling are the critical issues given consideration for the final design of Q390 stope and other such stopes within a Transverse Pillar. Communication and coordination between the different departments in the mine are essential for the necessary work to be completed in a timely manner to bring pillar stopes into production.

Jan 1, 2007

By L Mollison, K W. Mills, N R. P Baczynski, M F. Lee, I A. de Bruyn

This is the first of two papers concerned with rock stress inputs to various mine design issues at the large Ok Tedi open pit mine in Papua New Guinea. The companion paper (also published at this conference) is ‘The Application of Rock Stress Inputs to Stability Assessments at Ok Tedi Mine, Papua New Guinea’ (de Bruyn et al, 2014).Stresses are a required input for numerical modelling of mine design issues. However, for some operations, like the very large Ok Tedi open pit mine in remote rugged mountainous terrain, direct and representative measurement of rock stresses can be technically difficult and expensive. In such situations, development of an appropriate and sufficient understanding of rock stresses can be challenging.This was addressed for Ok Tedi by considering the following:The tectonic and regional geologic setting of the mine.Results from three different programs of rock stress measurement over 19 years, including hydraulic fracturing (1991), acoustic emission (2007) and overcoring (2010). Some interesting results of the overcoring work are discussed. It was done in a 4 km long drainage tunnel, which intersected a thick monzodiorite intrusive that has metamorphosed contacts to host contact Ieru Formation siltstones; anomalously low horizontal stresses were measured within the monzodiorite.Compilation of rock stress measurements from other New Guinea mines and prospects, both in Papua New Guinea and Indonesian West Papua.Comparisons between the variable Ok Tedi rock stresses and similar data from other porphyry copper deposits.CITATION:Lee, M F, Baczynski, N R P, Mills, K W, de Bruyn, I A and Mollison, L, 2014. Rock stresses at Ok Tedi, Papua New Guinea, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 337–346 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

This paper covers only the energy uses of natural resources and does not deal with non- energy uses, which in 1975 were of the order of 10 per cent of the total consumption of energy resources. The United Nations `J' Series of Statistics ex- presses each of the various forms of energy in terms of its coal equivalent in metric tonnes and this basis is followed in this paper. One tonne of black coal (referred to as tce) has been taken as the equivalent of the following. 29 X 109 joules or 27.5 X 106 Btu 0.68 tonnes or 4.8 barrels of crude oil 750 cubic metres or 26.5 X 103 cubic feet of natural gas 1 ò5 to 3.3 tonnes of peat or lignite (world average 2.54; Victorian brown coal 3 0) 8055 kWh (at 3.6 X 106 joules or 3412 Btu per kWh at 100% efficiency) 2660 kWh at 33% efficiency of generation 50 grams of uranium present in natural uranium reactors (see note later under nuclear energy) 0.8 grams natural uranium in breeder reactors Nuclear and hydro electricity are expressed as the coal equivalent required to produce, at 33 per cent efficiency, the same amount of electricity. In other words, electricity produced by these sources is converted to its coal equivalent at the rate of 2660 kWh = 1 tonne coal.

Jan 1, 1978

By C Hoffmann

Given that each year, 30–40 per cent of mining industry deaths are attributable to failures of vehicle interaction controls (EMESRT, 2023), the mining industry is now armed with a growing body of knowledge from EMESRT (Earth Moving Equipment Safety Round Table) and ICMM (International Council on Mining and Metals) global vehicle interaction initiatives over the past years, that enables mining companies, OEM’s and technology providers to work together to develop and implement more effective controls and drive the adoption of capable solutions. Leveraging 20 years of experience as a global technology provider of Proximity Detection System (PDS) and Collision Avoidance System (CAS) solutions for surface mining operations, Wabtec Digital Mine Technology shares key insights for ensuring the effective selection, implementation and integration of these technologies into existing mine site controls and mining operations for effectively reducing vehicle interaction risk enabling mines to drive towards ‘zero-harm’ objectives. Topics covered include: alignment with industry best practice for controlling vehicle interaction risk by EMESRT and ICMM, importance of the maturity of EMESRT levels 1–7 vehicle interaction (VI) control framework, managing expectations that PDS/CAS is a ‘silver bullet’, alignment with industry functional – performance – technical requirements, proximity detection versus collision avoidance, sensor performance and fusion and limitations, rules engine intelligence critical to mitigating nuisance alarms during normal operations, system health monitoring and reporting, human factors engineering and operator acceptance, implementation strategy, installation standards and quality control, change management program, training programs, reporting and data analytics with actionable insights and maintenance strategies. Insights will also be provided on the challenges moving from EMESRT levels 7 (operator awareness) and 8 (advisory controls) to level 9 (intervention controls) as it’s a journey not an out-of-box solution, the growing demand for coexistence of CAS and Autonomous Haulage Solutions (AHS), functional safety approach, value added systems integration and the applicability of new emerging technologies.

Apr 16, 2024

By M D. Taylor, G Duclaux, K Atkinson, L A. Fisher, A R. Latham, M F. Gazley, S J. de Beer, C M. Tutt

Geological logging by mine and exploration geologists involves the application of a logging code that requires a geologist to make a subjective decision to classify a particular rock unit. This will most likely result in inconsistencies in logging that will be difficult to monitor or assess over time. A potential solution to this problem is to have an objective method to determine the true nature of a given rock unit. This can be achieved using portable X-ray fluorescence technology (pXRF), as large geochemical data sets can be collected rapidly and at low cost. Plutonic Gold Mine (Plutonic), Western Australia, has a growing data set of more than 150 000 pXRF multi-element analyses from core and underground face samples, reconciled to Au fire-assay concentration, and logging codes. This study investigates and statistically validates the consistency with which the logging codes have been applied at Plutonic for the last four years, with respect to both Au distribution and other elements. In doing so, we have developed a schema that allows objective logging to occur once core has been sent for assay and analysed by pXRF. While far from replacing the geologist in the field, this is a complementary method that adds significant value to a data set.CITATION:Gazley, M F, Tutt, C M, Latham, A R, Duclaux, G, Fisher, L A, Taylor, M D, de Beer, S J and Atkinson, K, 2013. Objective geological logging using geochemical multi-element data - Plutonic Gold Mine, Western Australia, in Proceedings World Gold 2013 , pp 455-462 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By J Knecht, R Klymowsky, E Burchardt

The wide spread introduction of SAG mills into grinding circuits 20 years ago was the last development which had a major impact on the design and economics of comminution circuits. Single SAG mills were able to replace batteries of high maintenance and cost intensive crushers in order to achieve high throughput operations. Today, where the head grades of gold and copper ores are falling, there is again a strong need for a significant breakthrough to reduce investment and operating costs as well as improve metal recoveries. High-pressure grinding rolls is the new technology available to meet this challenge. HPGRÆs are state-of-the-art in several mining and minerals applications such as the grinding of iron ores and concentrates, and diamond bearing ores. Reasons for their success in these industries are overall cost reductions and improved product properties achieved by the application of high compressive forces. But these ores are relatively soft, with unconfined compressive strengths up to 150 Mpa.

Jan 1, 2000

By R Brown

The Singapore Land Transport Authority Contract C917A is for the design, construction and completion of all outstanding works under the original Contract 917, including taking over the design and construction responsibility for the works carried out by previous contractor. Construction works connect the bored tunnels between the stations at King Albert Park and Sixth Avenue on the Downtown Line two in Singapore.The original contractor became insolvent leaving the works incomplete. On 29 August 2013 McConnell Dowell were awarded the completion contract following a fast-tracked tender process. The completion contract required a quick start and therefore the recruitment of some of the original workforce. A large majority of the original workforce was from Malaysia, Indonesia, China, Philippines, Bangladesh, India and Thailand. In order to ensure that the safety standards were upheld, and that the new workforce embraced a safety culture, a behaviour based safety (BBS) approach was implemented.The BBS approach was implemented to overcome the existing poor cultural safety behaviours, and to ensure that high standards and expectations for safety were implemented. This ensured that the workforce were comfortable in identifying hazards, avoiding shortcuts, and changing poor safety behaviours.This article outlines how a BBS program was delivered on the C917A project, containing defined goals, communication tools, and assessment and feedback models.CITATION:Brown, R, 2014. Behaviour-based safety with a foreign-based workforce, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 65–68 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By F Ouchterlony

Soviet precursors to Cunningham’s Kuz-Ram model from 1983 are described. They are rooted in the mean fragment size and Rosin-Rammler (RR) fits to sieving data and rely on approximations. Three versions of the Kuz-Ram model are presented and all three are de facto based on the median fragment size x50, even if the term mean is used in the papers. This discrepancy caused Spathis in 2004 to suggest a correction procedure for the Kuz-Ram rock factor A, which was said to explain some of the missing fines in the model. This correction, while applicable to Cunningham’s 1983 paper, does not apply to his 1987 paper, in which he presents his own A factor.Common fixes of the Kuz-Ram model’s fines issue are fragmentation models where the fines are mainly generated in a crushed zone around a blasthole. This is contradicted by careful model blasting tests. The lack of a largest block size in the RR function may lead to spurious values of the uniformity coefficient n, eg in conjunction with image-based fragmentation measurements or crusher modelling. These issues may be solved by using the transformed RR function, which has a largest block size xmax or its replacement by the Swebrec function, such as in the KCO model.The mean to median issue is investigated in some detail and it is found that using x50 instead of the mean:has a sounder theoretical backgroundis less prone to errorsis not contradicted by the original Soviet data.It is finally suggested that future work on fragmentation prediction equations focus on the use of distribution independent quantities like percentiles, eg x50, x20 and x80. Some previous work in this direction is briefly analysed and one consequence is that the n-value of the Kuz-Ram model should depend on specific charge.CITATION:Ouchterlony, F, 2015. The median versus the mean fragment size and other issues with the Kuz-Ram model, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 109–120 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By Drinkwater DJ, Watsford RMS, Johnson NW, Munro PD

This paper describes the use of modelling and simulation techniques in the analysis and optimisation of grinding circuits at the Lead/Zinc Concentrator of Mount Isa Mines Limited.The objectives of the studies were to: -1. improve primary grinding circuit performance by reducing the production of -0.006 mm galena fines.2. maximise the fineness of grind in the second existing grinding power and pumping capacitie The study has shown that quantitative models can operations. The models described plant operation,,and simulated the effect of process changes on plant performanc The use of automated scanning electron microscope technology tcliberation characteristics of the major minerals in the Mount isa Lead/Li ore is also described.

Jan 1, 1985

NEARLY all problems in mining engineering involve the transport and distribution of materials from place to place, and in general the most economically managed mines and plants are those in which the transport of materials has been carried out most efficiently. Of all these transport problems, the hoisting of ore out of the mine and the distribution of same to the various treatment works is perhaps one of the most important. It is proposed in the present paper to traverse the conditions,affecting the location, scale of operations, and design of the main shaft and head gear at the Mount Morgan mine; afterwards describing the designs and workings of the shaft house, winding engine, and transport from the shaft house to the treatment works.LOCATIONWhen the copper-gold ore was developed sufficiently to determine approximately the boundaries of the ore-body, it was found that the existing vertical shafts would be wholly inadequate to deal with the increased quantity of ore required to be handled. It was proposed, therefore, to construct a new shaft, and to handle in this...

Jan 1, 1911

The Cannington silver lead zinc deposit is located near Mt Isa in North West Queensland. This world class orebody is owned by BHP World Minerals (BHP) and is estimated to contain 45 million tonnes of ore at an average grade of 11 per cent lead, four per cent zinc and 500 grams/tonne silver. At BHPÆs planned 1.5 Mtpa extraction rate, the mine life will exceed 20 years. Construction of the underground mine, which commenced in August 1993, was carried out by Peabody Resources Ltd (Mining Services Division) (PRL) for BHP Minerals Pty Limited (BHP) under contract packages totalling approximately $100 M using several innovative techniques to deliver safety, quality and time related project goals. Client/Contractor Partnering, resulting in harmonious working relationships, a combined commitment to the achievement of an excellent safety record, and a seamless transition from the construction phase to operation of the mine, has been a feature of the project.

Jan 1, 1998