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By U Singh

This paper presents the evolution of the studies and strategic plans to extend the life of operations at the Savage River iron ore project in north-western Tasmania. The current Life-of-Mine (LOM) plan for the Savage River operations is based on a series of open pits. Drilling has confirmed high-grade extensions of the magnetite resource at depths that exceed practical limits for open pit mining. Grange Resources Limited, the owner of the operation, is investigating underground options – not only to extend the LOM plan but also to maintain peak production at a reduced operating cost while reducing greenhouse gas emissions into the future. What makes this project unique is that it requires introducing a productive and cost-effective mining method to exploit a challenging geotechnical and geometrical orebody in an area of high rainfall. To support the study efforts, the development of an exploration decline, underground drilling programs, and an exploratory drive excavated into the orebody for geotechnical investigation was key to providing the necessary data for a pre-feasibility study (PFS). This paper describes the pragmatic approach and processes to developing the underground mining options study through data collection and then integrating these options into the open pit plans to optimise an overall strategic plan for the Savage River operations. The learnings for operators from this experience are how the technical and pragmatic approaches were aligned to develop the strategic plans, and the importance of timely investment in gathering the necessary data.

Mar 29, 2023

By D Roughsedge, J van der Sandt, L van den Berg

Axial flow fans are commonly used as auxiliary fans in underground mines to supply air to development headings. As diesel dilution requirements increase the fans used in conjunction with ventilation bags are becoming larger in diameter to move greater quantities of air over greater development distances. It is not uncommon for mining operations to sometimes use a number of these larger auxiliary fans with high airflow capacity in parallel as primary fans for the operations. These primary fan stations are often considered temporary installations and the fan selection and fan station design is rarely optimised. These temporary installations may become permanent resulting in an inefficient or unreliable primary ventilation system. A recent study looked at the likely causes of multiple primary fan failures at one operation with axial fans installed as primary units where the fan selection and fan station aerodynamic design was far from optimal. This paper explores some of the typical mechanisms of failure such as high pressure stall, unbalanced airflow, and fan tip speed as well as fabrication material. The paper proposes a number of good practise principles that should be considered during the design of a fan station. A second topic covered is the advantages and disadvantages of using different types of fans such as axial, mixed flow and centrifugal units. Here the concept of fan specific speed and its relevance to fan selection is discussed. Finally the paper quantifies the effect of using a high pressure auxiliary fan as a primary fan in a low pressure circuit, which may increase the mineÆs operation cost.CITATION:van der Sandt, J, van den Berg, L and Roughsedge, D, 2013. Practical considerations when using auxiliary axial flow fans as a primary mine fan, in Proceedings The Australian Mine Ventilation Conference , pp 63-70 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 1, 2013

By M Schmid

German hard coal mining operations have decreased for more than 40 years. Current political decisions are leading to a discontinuation of subsidised black coal mining by the year 2018. This decision will, however, be reviewed once again in the year 2012. The enormous increases in productivity, which were achieved in previous years, have so far not led to an achievement of market requirements. Coal mining at depth of more than 1200 m in multiple seam environments is not yet competitive in global comparison. In 2008 the 24 faces left in eight mines produced about 20 million tonnes of usable steam coal. Management and the workforce will be reduced in parallel; from today until 2012 by more than half. The average age of personnel is increasing dramatically and nearly no new personnel are recruited. With this background in mind, increasing continuously coal mining productivity becomes more and more difficult. Above all, this goal was reached by mechanisation, then by increasing the mining machine power and then by enhanced machine control systems. The first attempts to automatically operate full face equipment from above ground were in the early 1980s. After successful automation of the face equipment, the emphasis is now on mine logistics. Autonomous monorail transport was introduced and tested in 2007. Since the development rate of machine improvements has its limits, the focus is on the full interaction of the total production system. Here information technology (IT) becomes important; the driver for more productivity. Actual developments aim for the complete and general homogeneous IT infrastructure both above ground as well as underground. The explosive environment needs high level investments in safe technology, eg access points for WLAN and fibre optics for underground use (ATEX certification). New technology availability also drives the enhancements of management and process control systems. Innovations in the mining industry often comprise technology advances through the adoption of well-known technologies. With virtual reality (VR) teaching and training systems advanced computational instruments, both in software and hardware development, were applied in the German coal mining industry for ten years. Widening lists of applications as well as the encouraging achievements show the economical benefits of investing in virtual reality technology both for teaching and training and for knowledge management. The paper discusses the actual technical achievements as well as in IT infrastructure utilisation and also in employment of virtual reality based systems. Special focus and deeper insight will be given to the fibre optics and WLAN hardware integration as well as software developments. The pocket personal computer (PC) is used to enhance underground material transport and data acquisition. The knowledge-based maintenance system (KBMS) integrates real-time virtual reality knowledge elements, such as repair process descriptions. It gives access to expert documentation by intelligent search algorithms and 3D representations of major mining machinery.

Jan 1, 2008

The history and milestones in the evolution of support systems utilised in the mass-mined chrysotile mines of Shabanie and King are discussed in detail. The use of block caving, false footwall or sublevel caving mining methods brings with it some major support problems, which are exacerbated, in our low rock strength mining environments. The paper discusses the various support elements and systems that have been used successfully or otherwise in these operations. Some predictions for the future of rock reinforcing in our ground conditions are highlighted, in relation to geomechanics, levels of mechanisation and production risk analysis.

Jan 1, 2000

Safety bulletins and stickers issued for the paste backfill plant at Cannington read as follows: æCannington Paste Fill Plant, First of ItÆs Kind in AustraliaÆ. We could even dare to state that the Cannington plant is different than any other paste backfill plant in the world because of the overall design, plant equipment and underground delivery. However, one thing to be certain of is, the paste backfill plant works as designed and a pump is not required to deliver paste underground given the general plant arrangement at Cannington. The past two years have been a process of evolution to design and construct the plant and make it work. This paper will describe the paste process using full mill tails along with placement of cemented paste underground. Discussions will include rationale of fixed plant selection along with various control requirements. BHP World Minerals recently commissioned its paste backfill plant in December 1997. Cannington is placing full mill tails underground via two surface boreholes that deliver either to primary or secondary stopes.

Jan 1, 1998

By Resta S. A

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

Jan 1, 1994

IF lead be heated with concentrated sulphuric acid two distinct actions will usually be observed. In the first, bubbles begin to be evolved more or less rapidly from the lead, and in the second, which occurs at a higher temperature than the first, hydrogen and sulphur dioxide are evolved, free sulphur is liberated, and leadsulphate is formed. The second action may be violent and usually continues till the lead is all consumed.Attempts have been made to apply these reactions, by means of a standard procedure, as a "Flash test" for the acid resisting qualities of chemical sheet lead. The purpose of this article is to comment on the best method of performing the test, on the various phenomena which may be observed during the course of it and on the interpretation of the results when obtained.PREVIOUS WORKIn 1919, Barr...

Jan 1, 1930

By C J. McKenzie, D F. S Natusch

The lignite deposits of Southland and Central Otago are a potentially significant energy resource for New Zealand. Current estimates put the technically mineable lignite reserves at 5.3 billion tonnes, which is more than ten times the energy content of the Maui gas field. Thus, the strategic importance of the lignite as a basis for maintaining current levels of self-sufficiency in transport fuels, or as a possible feedstock for electricity generation, deserves full investigation. The full extent of the lignite deposits was only recently established as the result of a scout drilling programme undertaken between 1976 and 1979 by the Mines Division of the Ministry of Energy, and from companion studies conducted by the New Zealand Geological Survey. These discoveries of large quantities of lignite coupled, at the time, with rising oil prices, raised the prospect of their development for production of transport fuels.

Jan 1, 1983

By G Campbell-Cowan

Much has been written about the fact that most transformation efforts disappoint. This paper addresses factors that should be taken into consideration in planning and implementing transformation programs to ensure success.In 2009, St Barbara commenced a transformation program to address issues of chronic poor quarterly operational performance; financial pressure caused by the unreliable operational performance; and an inability to develop business plans with integrity and to reliably deliver on the plans. As a result of a number of years of disappointing operational performance, St BarbaraÆs culture was not conducive to business success.This paper uses lessons learnt during St BarbaraÆs transformation program to highlight key characteristics of change programs that can generate significant sustainable benefits. While there were many benefits from the transformation program, the most significant impacts of St BarbaraÆs program have been transformation of the companyÆs culture and capability of people as business leaders; the establishment of a business systems framework to guide the design and development of systems; and developing support functions, for example centralised procurement and supply chain, business improvement and technical services.CITATION:Campbell-Cowan, G, 2012. Business transformation - Lessons learnt for successful change, in Proceedings International Mine Management 2012, pp 135-142 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 20, 2012

By G M. Jeffress, D C. Arne

There are two discrete aspects to collecting portable X-ray fluorescence (pXRF) data to obtain reliable results and to comply with reporting requirements under the 2012 edition of the JORC Code (JORC, 2012) – sampling method and quality assurance. A robust sampling program is required to obtain representative material for analysis. The appropriate method should be established for a particular project using a small orientation study. A variety of approaches to sampling soils, drill cuttings, rock faces and diamond drill core are discussed. These include using multiple spot analyses, scanning using a single operating beam and the collection of cutting saw pulps. The operator must also be aware of the attenuating effects of analysing through sample bags of different material types for various elements as well as the limitations of current pXRF instruments in reporting reliable data for certain elements. The analysis of the samples must also be accompanied by a quality assurance program in order to generate data that are ‘fit for purpose’. This includes recording X-ray tube resolution on a routine basis, using matrix-appropriate standards for which total elemental concentrations are available, using silica blanks, capturing sufficient duplicate analyses to constrain data precision and obtaining check assays to calibrate pXRF data against laboratory data. Examples of quality control approaches and data are presented. Table 1 of the 2012 JORC Code also recommends that information on instrument make and model, reading times and calibration be provided in any reporting of pXRF data. To this should be added information on operating mode and temperature, software version and moisture content of the samples. A robust sampling methodology with a suitable quality assurance/quality control program should produce pXRF data of sufficient quality for public reporting purposes, provided that the data are presented using appropriate cautionary language and adequate supporting information.CITATION:Arne, D C and Jeffress, G M, 2014. Sampling and analysis for public reporting of portable x-ray fluorescence data under the 2012 edition of the JORC Code, in Proceedings Sampling 2014 , pp 57–64 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 29, 2014

By S C. Dominy

Grade control programs aim to deliver economic tonnes to the mill via accurate definition of ore and waste. The foundation of a successful program is high quality sampling supported by geology and a suitable data management and modelling system. Underground sampling methods include chip, channel and panel samples; grab/muck pile samples; and drill-based samples. Grade control strategy is related to mining method and orebody type. Sampling protocols must be designed to suit the style of mineralisation in question. Holistic studies focussing on ore mineralogy and gold particle deportment, size and distribution are required for sample collection and preparation protocol optimisation through ‘Theory of Sampling’ application. Where possible, such programs should be undertaken early in the life of a project. Appropriate assaying procedures are also required. Program implementation will require suitably skilled individuals to train and mentor staff, with ongoing Quality Assurance/Quality Control (QA/QC) monitoring and review will allow protocols and staff to be updated as required.

Aug 22, 2011

By D Morrison, P Goodman

The cycle time between adjacent stopes is critical to achieving the required production rate from 3500 Orebody; one of the Enterprise Mine orebodies. Current Mt Isa cemented fills require a 90-day cure period which had to be cut to 30 days while maintaining the required strength criteria. The Enterprise Mine Feasibility Study recommended that this be achieved by Cemented Slurry Rock Fill (CSRF), but that on-going research into paste fill be continued. The continuation of the research, in conjunction with overseas visits has recommended that the 3500 Orebody be filled with paste fill, with the potential to fill other orebodies. The paste fill will comprise cyclone and thickener dewatered copper tailings to which Portland Cement (PC) is added before vertical borehole delivery and undergound pipeline reticulation to individual stopes. The benefit is not only re-use of copper tailings but also much reduced binder usage.

Jan 1, 1998

By F D Durao, Muge F. H, Rogado J. Q

In the scope of the project named CAPUME II (EEC BRITE/EURAM contract - project MA2M-CT90,-0042(SMA)) for the development of an integrated mine planning system for underground mines, two of the main tasks were the development of a short-term mining planning procedure (module) and a numerical simulator of the mineral processing plant of Pirites Alentejanas - PA. The short-term mining planning module defines the mining sequences by solving a constrained minimisation problem. The ore grade variability is the objective function subject to the geometrical constraints of the mining method and to the maximum of `internal blending'. The optimisation problem is solved by applying a dynamic programming algorithm. The plant simulator is an essential tool of the planning system allowing the preview of metal grades/recoveries of copper, lead and zinc of concentrates streams, given the corresponding metal assays of the run-of-mine ore, defined by the short-term mine planning module. This way, the management can plan the short-term mining operations (the weekly sequence of exploration blocks and the internal planning) in order to fulfill given required conditions, based on a shipment schedule and on a purchaser's formula. In this paper, after a short description of the short-term mining planning module and of the simulation package named SIMUL, a synthesis of the main model development steps and the results of some simulation runs are presented and discussed.

Jan 1, 1995

By M Costa, L Polizzi

Process optimisation and continuous improvement are usually acknowledged when making a process more effective, efficient and transparent. During the last few decades, thousands of companies around the world have used total quality concepts in order to establish a continuous improvement process in their companies. Typically these companies apply some kind of Kaizen-type tools and expect results in the short term; however, the great majority of companies are poorly implementing these continuous improvement programs.Usually the most common reasons for failure of the program are lack of commitment from leaders, lack of discipline and engagement from the team to follow process and lack of clear targets for the program. When the results do not come at the expected timeline, it is common to simply drop the current process and apply a different approach from another company or consulting firm.This paper will explore some successful cases of companies that have invested time and effort to establish a reliable and sustainable process of continuous improvement. The focus will be case studies of mines and smelters around the world that use the plan–do–check–act (PDCA) cycle to increase productivity with the best services and lowest costs. The main tools and processes used by these companies will be discussed, as well as results achieved.CITATION:Costa, M and Polizzi, L, 2014. Introducing and sustaining a continuous improvement program in mines and smelters, in Proceedings 12th AusIMM Mill Operators’ Conference 2014 , pp 55–62 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 1, 2014

By J T. Smit

The theory of froth flotation developed slowly, in almost all cases lagging behind practical developments in the operation of flotation processes. This was largely the result of a lack of understanding of the required basic principles of chemistry and physics, many of which were being developed at the same time. A review of some of the early theories propounded is worthwhile, and should encourage those who are presently studying or practicing flotation to exercise some care in claiming a complete understanding of the underlying phenomena in the art. This paper considers theories presented up to and including those in Principles of Mineral Dressing by Antoine M Gaudin (1939). Of course, developments since that time are important, but they are beyond the scope of this discussion.

Jan 1, 2005

By R Redden

"The Didipio Gold-Copper project in the Philippines has been a well-defined reasonably high gold grade porphyry for almost two decades. OceanaGold are now bringing the project into production in late 2012 and have recently reoptimised the project with the goal of combining the inherent high grades with higher through-put than previously proposed that will see strong initial metal production. The project was discovered and well defined by 1995, but has seen some obstacles to development, namely sovereign risk, capital cost and project funding. The project strengths over this time that have kept the flames alive are: strong grades large orebody with low stripping ratios a simple beneficiation process and a clean high-grade concentrate strong support from the Philippines government.The initial study in 1998 used Gold and Copper price assumptions of $325/oz and $0.95 lb respectively. Today reserves are based on $950 and $2.85. So, being a porphyry with a large reducing grade halo, the deposit now lends itself to extraction on a much larger scale than before, without any significant capital expenditure as a larger open pit now dominates the project.Didipio is a game changer for OceanaGold, so it has been important to learn from history and to capitalise on a strong initial metal production profile. The project sits in a reasonably remote mountainous area of Luzon which sees annual typhoons and numerous short duration high intensity rainfall events and two rivers flowing through the project area, so it has not been without some innovative technical solutions.CITATION:Redden, R, 2012. Didipio - Learning the lessons, adapting and getting ready for production, in Proceedings Project Evaluation 2012, pp 67-76 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

May 24, 2012

By Kwitko G

Exploration for coal has been on-going in South Australia for the past 100 years. During this period substantial resources of low rank coal have been delineated throughout the State. These deposits are of variable quality often with high moisture, sodium, chlorine, sulphur and ash content and although generally regarded as suitable for use in conventional pulverised fuel boilers, many are difficult to utilise. The only operating coal mine in South Australia is at Leigh Creek where coal bearing shale was discovered by chance in 1888 during excavation of a railway dam near the township of Copley. Leigh Creek has had a very diverse mining history from the initial small scale underground mining through to open-cut mining utilising draglines and more recently large shovels and trucks.

Jan 1, 1992

By B Jones, M Chappell

Permanent rock bolts used to support rock tunnels are required to perform for the design life of the structure as a minimum. Quality of installation is critical to the performance over the life of the rock bolt.This paper will present the findings from an in investigation into the integrity of rock bolts installed in an underground hydroelectric power station cavern and access tunnel. The 25?mm diameter rock bolts were installed 50 years ago, tensioned and post cement grouted. Due to a major machine upgrade the whole facility was subject to an asset survey. The owners are responsible for managing the risks associated with the failure of these rock bolts and ensuring the structural integrity of the tunnels and caverns is maintained to continue operations, protect machinery, assure production and more importantly maintain a safe working environment for all employees and visitors.To help manage risk a proactive approach is desired. To this end a test schedule using a non-destructive testing (NDT) system was carried out by Independent Integrity Testing Pty Ltd (i2t). The system used in this application was RokTel™. The system operates by applying a small axial impact to the rock bolt end and measuring the resultant acceleration response. The rock bolt characteristics affect the acceleration response.The data output from the system is analysed principally using Fourier Analysis (FFT) and sinusoidal waves. The energy generated in the bar, the rate of damping and changes in frequency are all assessed. Testing was carried out on 70 rock bolts within the tunnel and cavern. A selection were then over cored, photographed and documented. The data gathered from the testing is then correlated with physical evidence to establish a calibration for the remainder of the rock bolts and assess if this is a viable method for identifying defective elements, and what degree of accuracy can be achieved. The findings will assist with the future assessment of similar hard rock underground?facilities.CITATION:Jones, B and Chappell, M, 2014. The use of non-destructive testing to identify defective rock bolts – a case study, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 275–280 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By B Olsson, R Norman, M Volz

Australia has seen unprecedented demand for coal exports in the last ten years and this demand is set to expand further still according to many analysts. This rapid increase in demand has placed pressure on multi-user coal chains to guarantee the capability to meet the required demand, in terms of both current operations and capacity expansion.The projects required to deliver these forecast tonnages take place in an increasingly complex commercial and technical environment. These challenges include brownfield and greenfield projects, multiple rail and terminal service providers as well as a myriad of mine operators, all needing to operate in an increasingly integrated manner to get the most out of expensive shared assets.Increasing complexity and integration drives the need for more holistic and sophisticated analysis tools. The capacity of coal chain subsystems, such as mine, rail and port, can no longer be determined effectively in isolation. Understanding the nature of the interactions between these subsystems and the resultant capacity of the integrated system is the key to maximising value. TSG advocates the use of a total integrated system approach to understand the behaviour and performance of complex coal chains.Recently, TSG has worked in conjunction with the Integrated Logistics Company and a number of stakeholders in the Dalrymple Bay Coal Chain to deliver the first independent system master plan. This master plan has provided a quantitative and rational assessment of coal chain capacity in its current state and a prediction of its capacity once a pipeline of committed capacity improvements is in place. It is underpinned by a highly detailed discrete-event simulation model of the complete coal chain as an integrated system, including mine load-outs, rail, terminal and port operations.This paper provides an overview of the study and describes the differences between subsystem and total integrated system model performance.

Sep 26, 2011

By T D. H McGrath, J P. Vaughan, J Heath, J J. Eksteen

A reliable laboratory method to characterise the response of free gold particles when subjected to flash flotation conditions has been developed by AMIRA P420 researchers at Curtin University. This test has been applied to assess the flotation recovery of gravity recoverable gold from free milling ores as well as synthetic ores featuring either a gravity concentrate or gold powder. Trends in free gold flotation kinetics as well as size and milling effects were identified for gold recovery, based on the different gold types, reagent dosage and residence time.CITATION:McGrath, T D H, Eksteen, J J, Vaughan, J P and Heath, J, 2013. Laboratory flash flotation trends for a variety of gold particles, in Proceedings World Gold 2013 , pp 357-366 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013