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By M Pizey

After 60 years of operation, coal extraction at Solid Energy New ZealandÆs (SENZ) Strongman Mine, near Rapahoe is scheduled to end in early 2005. Up until 2003 the closure bond for Strongman Mine was only $930, and both SENZ and the West Coast Regional Council (WCRC) agreed that a more realistic level of bonding was required.   A conceptual closure plan has been developed by Golder Associates, and the cost of the work estimated. Closure includes decommissioning of equipment and facilities, rehabilitation and replanting of all disturbed areas and a period of maintenance and monitoring to verify that closure objectives have been met. Significant maintenance allowances are included to cover management of underground fire, subsidence and slope instability. These make up much of the potential ongoing environmental liability at the Strongman. All costs incurred beyond year 1 of closure are discounted to present value. Uncertainty in costs is addressed by Monte Carlo simulation, with an 80 % confidence level adopted.   A bond quantum of $3.0 million has been calculated for the first year of closure at Strongman. A three-year ærollingÆ bond is proposed. Progress will be reviewed annually, with the bond adjusted up or down accordingly. It is then renewed for a further three years. This allows for progressive return of the bond as rehabilitation objectives are met and verified. Similarly, if there are delays in meeting objectives, a proportion of the bond may need to be kept in place for a longer period than assumed. The level of bonding in place for the Strongman operation at any time in the future will therefore reflect the cost to complete the closure work programme.

Jan 1, 2004

By A Kindred

The Bogong Hydropower Development is a 140 MW high head power project currently under construction in Northern Victoria. The project is the final link in the Kiewa hydroelectricity scheme, which was originally constructed in the 1950s. Due to its location in the Alpine National Park, the waterway for the Bogong project must be located entirely underground. A series of shafts and tunnels is being constructed to transfer the water from the headworks at McKay Creek to the new power station located on the shores of Lake Guy in Bogong village. The difference in elevation between the headworks and the power station is greater than 420 m, which poses particular issues for the design and construction of the waterway. The purpose of this paper is to describe the design and construction planning aspects of the tunnelling and shaft excavation and lining works for the waterway. The tunnelling works includes 5.7 km of hard rock tunnel boring machine (TBM) driven tunnel, 1.1 km of drill and blast tunnel and two deep shafts. The tunnels and shafts are lined with a mixture of permanent rock bolts and shotcrete, concrete lining and steel lining. The viability of the Bogong Hydropower Development relies heavily on the ability of the TBM to excavate at high speed through the East Kiewa Grandiorites. Particular attention was given during the construction planning stage to understanding the excavation characteristics of this material, and designing a suitable hard rock TBM that would be capable of meeting the program requirements of the project.

Jan 1, 2008

Projects to be undertaken in remote locations require special attention with regard to constructability from the very first stages of design. This is to ensure not only that the project is compatible with the environment in which it' is proposed to be built, but that it does not require facilities or special construction equipment and expertise that is not available in the proposed location. This paper draws on experiences gained on projects in Alaska, Northern Canada, South East Asia, outback Australia, and more recently Bougainville, in Papua New Guinea, where over the past 5 years Minenco has undertaken in excess of A$120 million of work on a number of different projects for Bougainville Copper Limited Although many of these projects have been close to large populous cities, which have been served by regular shipping and airline services, the locations have not had the availability of construction facilities which exist in major cities of Australia and thus can only be considered as remote locations by current day standards. As a result, every nut bolt and washer has had to be brought to the job site by the construction company. No hardware or electrical warehouses existed for those forgotten half dozen high tensile bolts, spring

Jan 1, 1986

By J Zhang, O Ostrovski, C Zhang D Cai, Q Wang

The conventional CaO-SiO2-based mould fluxes are not suitable for high-Al steel casting because of the strong reaction between silica in the flux and aluminium in the steel strand. In the process of casting of high-Al steel, flux composition changes; with the decrease of the silica concentration and increase of alumina. Knowledge and understanding of the effect of the Al2O3/SiO2 ratio on flux structure and properties are useful for flux design for the high Al-steel continuous casting. This paper investigated the effect of the Al2O3/SiO2 ratio on structure, viscosity, phase composition of fluxes quenched at different temperatures and heat transfer of CaO-Al2O3-SiO2-B2O3-Na2O-Li2OMgO- F fluxes. It was found that flux melting temperature increased with the increase in Al2O3/SiO2 ratio. Viscosity of the flux melts increased significantly with the increase of the Al2O3/SiO2 ratio from 0.7 to 1.2, reaching the maximum value, and then decreased with further increase of the Al2O3/SiO2 ratio. Raman spectroscopy analysis revealed that the change of the Al2O3/SiO2 ratio led to the change of aluminate and silicate structural units. The turning point for viscosity was attributed to the change in the degree of flux polymerisation. X-ray diffraction (XRD) analysis showed that increasing Al2O3/SiO2 ratio increased crystallisation tendency of the fluxes. Heat transfer measurement by infrared emitter technique (IET) revealed that increasing Al2O3/SiO2 ratio led to the decrease in heat flux which is correlated well with the increased crystallinity of the flux. The results suggested that the flux with Al2O3/SiO2 ratio 4.3 is the best candidate among the studied CaO-Al2O3-based mould fluxes for casting of high-Al steel.

Aug 21, 2024

By D Head

IonicRE acknowledges within our mining industry, there is a common belief that workplace health and safety, often referred to as safety, is just a matter of ‘common sense’ – something obvious and easy. However, at IonicRE, we hold a different perspective. We understand that safety is far from easy. We recognise the need to emphasise the importance of understanding and conveying the inherent difficulties of working safely. We are committed to implementing processes that support individuals in achieving our safety objective of eliminating fatalities and permanently disabling injuries. To build resilience and sustainability into safety performance, we draw parallels with the principles underpinning sustainable and exceptional production performance. Achieving sustainable safety performance demands effective leadership, meticulous planning, adept management, genuine care and unwavering commitment. We’ve leveraged various tools and techniques, such as DISC theory, Maslow’s hierarchy, process control, Kaizen, Six Sigma and Kirkpatrick’s 4 levels, among others, to facilitate this improvement. There methods play a pivotal role in developing a Safety Blueprint for enhanced safety performance. This paper provides an overview of IonicRE’s Safety Blueprint, a strategic framework for developing our safety capability. Our capability is underpinned by three key pillars. Firstly, a comprehensive risk management approach is imperative, encompassing the understanding of hazards, the identification of threats to our people and the associated risks. Secondly, it entails providing and enforcing accountability to sustain our safety capability. Lastly, it involves constructing an effective defence system against threats and harm. Implementing these pillars requires a meticulously devised change process. Anticipating resistance and potential setbacks, we underscore the importance of having the right people and a wellcommunicated vision for safety at IonicRE. A Safety Blueprint serves as a detailed plan outlining the path toward a future goal. At IonicRE, we contend that safety in the mining industry has generally lacked a coherent and effective Safety Blueprint – a comprehensive plan to navigate the journey toward a destination. Drawing parallels with NASA’s detailed plan for landing a man on the moon safely, we question why, as an industry, we cannot similarly eliminate fatalities. While progress has been made in the last century, we must not wait another 50 years to eradicate fatalities from our industry. Examining Safe Work Australia data from 2008 reveals that 47 per cent of mining fatalities result from vehicle activity and 40 per cent stem from individuals being struck by an object. As of December 7, 2023, seven lives have been lost in the mining industry in Australia this year, indicating a stubborn trend mirroring 2022, with limited improvement over the past 25 years. These incidents are not isolated or unexpected. We understand the hazards and controls, yet fatalities persist. IonicRE considers that the mining industry stands at a critical juncture – do we accept a plateau in mining safety performance, or do we rethink our approach? At IonicRE, we are thoroughly reassessing the hazards that threaten our people, systematically redefining effective risk control measures and establishing a robust framework to hold individuals accountable for the effective implementation of the control measure.

Apr 16, 2024

By M Angus, S Konopa, A Virisheff, S Crispin

A positive mill reconciliation at a mine is a double-edged-sword. Much back slapping happens. The bank and the board can’t get enough until the downside becomes apparent. Over a prolonged period, there becomes an issue with market perception and the potential for shareholders to be misinformed regarding the potential value of the project. In addition, there are impacts on mine scheduling, waste allocation (or lack thereof), government expectations, and the potential for misguided external assumptions regarding the ‘unexpected’ results. The PT Agincourt Resources Martabe Gold Mine has shown a significant under-call, in the order of 20% total gold metal, between the Mineral Resource (MR) estimates and Grade Control (GC) estimates since production commenced in 2012. Recently, the under-call has been reduced by incorporating the use of grade control drilling in the MR grade estimates. Despite recent improvements in reconciliation, drilling in 2017 at both Purnama and Barani open pits shows that infill reverse circulation (RC) drill holes often produce significantly higher grades than those predicted in the MR block model. CITATION: Angus, M, Virisheff, A, Konopa, S and Crispin, S, 2018. Martabe Gold Mine, Indonesia: a positive solution for positive reconciliation, in Proceedings Complex Orebodies Conference 2018, pp 76–78 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

Direct smelting of copper in a single vessel has long been the extractive metallurgist's dream. Such a process offers the important alvantage. of (i) maximum use of the energy available from oxidizing the sulphur and iron of the concentrate: (ii) restriction of SO2 emissions to a single constant-strength source; (iii) minimum materials handling and (iv) elim-ination of at least one process step. Extensive developmental work was carried out in the 1960's and 1970's to implement such single-step processes. Some of the processes reached the prototype stage and it appeared that copper smelting technology was on the thresthold of a new, efficient, minimum-pollution era. Since that time, however, the forward thrust has slowed and single-step copper smelting is still a process of the future.The paper describes the potential advan-tages of single-step smelting; its history and current status; and the reasons why it has not been adopted industrially. It concludes that the potential benefits of single-step smelting are powerful and that many of the difficulties encountered in the 1970's will be overcome in the 1980's.

Jan 1, 1985

By F Melcher, M Wiedicke, A Wittenberg

Ferromanganese nodules form a specific category of widespread marine mineral deposits. The tremendous increase in metal prices during the last decade raised new economic interest in their exploration. The German Federal Institute for Geosciences and Natural Resources (BGR), which had been engaged in nodule research in the 1970s and 1980s, renewed its activities on this subject based on an exploration contract with the International Seabed Authority, signed in 2006. BGRÆs licence area û comprising 75 000 km2 û is located between the Clarion and the Clipperton Fracture Zones. In this so-called nodule belt north of the equator the sea floor reaches water depths of >4000 m. About 900 million tonnes of manganese nodules are expected there. In this study the fine-scale distribution of important elements in manganese nodules and crusts from a variety of locations was investigated. Besides 11 samples from the RV SONNE cruise SO-25, numerous samples from additional locations were included in this study for comparison. In general, the sample suite includes two genetic types of precipitates, manganese nodules and Co-rich crusts. A detailed characterisation of the distribution of major, minor and important trace elements in manganese nodules based on in situ microenergy dispersive X-ray fluorescence (¦-EDXRF) analysis is presented here. The data are compared with bulk major, minor and trace element data as well as with quantitative electron probe microanalysis (EMPA) data sets. The element distribution maps and profiles produced by ¦-EDXRF analysis with short or extended (in case of profiles) counting times, allow precise selection of æregions of interestÆ for further detailed investigation using high spatial resolution techniques (eg scanning electron microscope (SEM)-EDAX; laser ablation-inductively coupled plasma mass spectroscopy (LA-ICPMS); isotopic studies).

Jan 1, 2008

By Scaife PH, Cripps Clark J, Cameron DB

Tuyere coke samples have been taken through the tuyere openings of B.H.P. International Blast Furnaces since 1978 with Whyalla No. 2 Blast Furnace taking samples on a regular basis since 1982. The degradation of coke during it's passage through the Blast Furnace can be measured and the relationships between these data, feed coke data and blast furnace operating data demonstrated. Tuyere coke sampling has been useful in revealing misleading external coke testing results and is still the method to monitor directly the performance of coke within the Blast Furnace.

Jan 1, 1987

The CSIRO acid alumina employs the essential steps of digestion, hydrolysis and calcination to produce pure alumina from ores too high in silica or too low in grade for the Bayer process. The two latter stages have been described in some detail previously but the digestion stage requires separate dis-cussion since ores vary widely in composition and reactivity. Kaolinitic clays require. roasting to 8000C to render the alumina soluble in the 11 per cent sulphuric acid used in the process while some ferruginous laterites require roasting to reduce the reactivity of iron minerals. The iron content of pregnant solutions is kept at a low figure by digesting at temperatures where the solubilities of ferric oxide or basic ferric sulphates are small. A.two-stage, counter-current digestion is necessary to extract a high percentage of alumina from the ores and to pro-duce a basic pregnant liquor, with an S03:Al203 ratio of 1. 9 suitable for high temperature hydrolysis. The second stage of digestion, called the modification stage, treats slightly acid liquors with exces's of ore in the temperature range 1200- 1400C. The first stage operates at 1700-190 C to extract further alumina from modification residues, using recycled acid obtained from later steps of the process. Both temperature ranges are critical for economic operation and for proper con-trol of the iron content of solutions. In batch experiments, thirty minutes is regarded as a suitable retention time for digestion and modification; ores which require much longer than this are less suitable for the process. Impurities. such assilica, titanium and vanadium oxides are discarded in the residue along with iron oxide and do not contaminate the final product. Bivalent metallic sulphates such as MgSO4 can build up in the circuit to a very considerable degree without affecting. product purity.Comparison with other processes shows that the C. S. I. R. O. process is superior for control of contamination by iron, which is the major problem in acid processes. The pure intermediate product (3 A1203. 4 S03. 9 H2O) is also more convenient for cal-cination to alumina than the hydrated aluminium sulphate usually recovered in other processes. Detailed cost comparisons must await pilot-plant evaluation of the C. S. I. R. O. process.

Jan 1, 1963

Spiral separators have been used to treat heavy mineralsands in Australia for some 35 years. During the last five years the logical extension of this technology has been torecover cassiterite from alluvial deposits. Plants incorporating spirals are already operating in Indonesian andAustralian tin mines. A more fundamental understanding of the design of spiral separators has recently led to their use in other mineral treatment plants.In particular, the treatment of alluvial gold and fine coal has been most successful. The new generation of spirals that has been developed to treat these minerals is more easily operated than other competing processes and is therefore ideal for new mine situations.

Jan 1, 1986

By Jancar T, de Guzman M M, Matthews B, Tu J. Y

The use of computational simulation to predict the performance of existing equipment or for the design of improved mineral processing equipment will be referred to as Computational Mineral Processing (CMP) in this paper. The emphasis will be on solving the governing equations for liquid solid flows in complex geometric domains to obtain, typically, the three-dimensional distributions of velocity and pressure for the liquid phase and the velocity and concentration for the solid phase. The underlying technology, computational fluid dynamics (CFD), is very well-developed in other industries (aircraft, car and chemical) and forms a vital part of product design and analysis. The subsequent design of improved mineral processing equipment may also involve finite element structural analysis (FESA). Computational fluid dynamics (CFD) and finite element structural analysis (FESA) are part of the generic discipline of Computational Engineering and Science (CES). Ciment and Scherlis (1993) define CES as `The systematic application of computing systems and computational solution techniques to mathematical models formulated to describe and simulate phenomena of scientific and engineering interest'. Increasing computer power (Kaufmann and Smarr, 1993), is a dominant factor determining the rapid growth of industrial utilisation of CES. This increase is happening at both the supercomputer and the workstation level. Indeed, today's typical workstation, a Hewlett-Packard 735, is as powerful as a CDC 7600, the leading supercomputer in 1970. Future computer architectures are expected to become increasingly parallel (Gartner Group, 1990) allowing a sustained performance of a teraflop (a million megaflops) to be achieved well before the Sydney Olympics in the year 2000. It is recognised that the modem development of most disciplines in the physical sciences rests on the three complementary strategies of experimentation, analysis and computational simulation. As the 21st century is approached the volume of computational simulation, both fundamental and applied, is growing dramatically and the role of experimentation is diminishing. In the area of equipment design, CES provides the following advantages over experimental testing and measurement: 1. lead time in design and development is significantly reduced; 2. CES can simulate conditions not reproducible in experimental tests; 3. CES provides detailed and comprehensive information; and 4. CES is more cost-effective and time-efficient. The ultimate benefit for industry is greater productivity and hence greater profitability. The broader issues in relation to CFD are discussed by Fletcher (1993b). In the five- to ten-year time frame, growth in computer power will make it practical to combine CFD and FESA with optimisation procedures to produce a design process that is almost fully computerised. It is expected that fully automatic

Jan 1, 1995

By Qixiang Y

The strength of coal mass saturated with gas is an essential parameter in studying the mechanism of gas and coal outburst,and its prediction method. Up to now, there has not been a method for determining the strength of coal mass saturated with gas.This paper describes a new method whereby the strength of in-situ coal mass can be determined and stored continuously and automatically. The simulation results obtained in the laboratory indicate that the new method allows a fast, reliable, inexpensive and convenient determination of the strength of coal mass.

Jan 1, 1992

By Thomas R

The successful `marriage' between a company seeking to raise funds to develop a project and their financiers calls for a strong mutual understanding of each other's needs. For a company attempting to raise funding, the alternative methods are ever expanding. The optimum method will vary depending on the financial position, risk/reward outlook of the company and the strength of the project for which development capital is being sought. It is likely that small mining companies will need to raise equity funds for advancing projects to the development stage. At that time, they will probably still require a reasonable level of shareholder equity to meet the requirements of banks and other parties to cover potential cost over-runs on the project and feasibility costs. Larger companies, however, are likely to find it much easier and cheaper to raise debt from banks. When evaluating companies and projects for funding, banks will pay particular attention to the quality and experience of management in developing similar projects and it may be necessary for some companies to retain the services of outside consultants. Before a project needs funding, companies should meet with potential financiers to develop relationships to select and ensure a smooth transaction to funding in the future.

Jan 1, 1997

The correct design and effective operating strategies of metallurgical plants require a constant analysis of data gathered for process control, or for due accountability. Conventional, oldfashion statistical tools often fall short of helping management, either because they are too complicated and ambiguous, or because they fail to address structural problems leading to causes of setbacks. This paper focuses on three statistical tools known for their practicality and the in-depth perspective they offer in attempts to retrieve important information from existing data. These tools also provide a better appreciation of the importance of carefully selected data quality objectives. Chronological data are meticulously gathered and stored at considerable expense: They have value, and it is the duty of management to take full advantage of them. These three selected tools are the variogram and its auxiliary functions, the moving average and its auxiliary functions, and the relative difference plot. This paper offers solutions, and a reference for managers to optimise metallurgical plants.

Jan 1, 2002

By Stewart Gillies AD

Resource rent taxes are taxes which only become effective at such a time as a pre-determined rate of return has been achieved by an operation. Resource Rent Taxes have from time to time been considered for implementation in both Australia and New Zealand. The offshore petroleum industry in Australia is already subject to RRT as is the Roxby Downs (Olympic Dam) Mine in South Australia. Both the mining and petroleum taxation regimes in Papua New Guinea include a resource rent tax component called Additional Profits Tax.

Jan 1, 1995

Computers are playing an increasing role in the management of technical data in mines. Companies are re-assessing the role of their data processing departments as users demand computer resources in non-accounting areas. Data of all kinds is now being seen as a, company resource, and the role of computing professionals is to help to manage the data flow, not merely to manage computers. The concept of distributed data bases puts the responsibility for data entry, editing and updating with the user. This challenges conservative views of centralized control of computing, suggesting, instead, centralized co-ordination. A survey of the possible applications of computers in technical areas points up the special requirements of handling raw, processed and consolidated technical data. Technical data bases have become flexible as mini- computer hardware and software have rapidly developed. Management has the ultimate responsibility for efficiently administering corporate data bases, and it must ensure suitable policies are developed for this purpose, with enough flexibility to cope with the impact of fast changing technology.

Jan 1, 1980

The provision of electrical power is an important consideration in project develop- ment. The first step to be taken in this area is to assess the power requirements of the project. The alternatives of taking a supply from a power authority or providing local generation can then be considered. This requires additional definition of the prob- able characteristics of the supply. The availability of authority power in Australia is limited by the extent of the state power grids. Recent developments now allow these grids to be extended and their load capacity increased to meet major load increases at less cost than was possible pre- viously. The options for local generation include diesel, gas turbine, steam, hydro, solar and wind, each having its particular performance characteristics and costs. The choice of fuel for diesel, gas turbine, and steam plant likewise involves consideration of a range of factors. The arrangements adopted for a number of development projects illustrate some of the aspects which influence the decisions on power supply.

Jan 1, 1986

Diversification has characterised the mining industry in this country and globally in recent decades, and in Western Australia in particular. One of the most obvious aspects of diversification is technological change which continues at a rapid and sometimes bewildering pace. A function of technological advances is the increased capacity to further diversify the range of minerals which can be identified in economic concentrations and profitably extracted. This broadening of the total base of the industry has a synergistic effect on its further development by extending its geographical spread and increasing scope for decentralised infrastructure. Another aspect of diversification is the corporate thrust towards establishing overseas mining bases for a variety of reasons. Off-shore (sea bed) mining is a further manifestation of increasing diversity, although very much in its infancy.

Jan 1, 1996

By Shuqing L

The application of single liquid cement for fracture grouting in base rock may have history more than 120 years. The disadvantage of it is difficult to increase the grouting efficiency, because the jelling time of it is very long and hard to control. The double liquid grout, such as chemical grouts and cement water glass grout was developed at the end of 1960.'s Although the jelling time of this kind of grout can be controlled, it mast adopt double liquid grouting technology, use complicated equipment and is not easy to control component's ratio of the grout. Another disadvantage for chemical grout is high price, and have pollution to environment. OCE series single liquid grout is the effective grout material developed recently by making large efforts in Ohina. Main feature of it is that the jelling time is easy to control, materials from cement and clay are very cheap and without pollution to environment, and the grout can be injected by single liquid technology. The effect of QCE series grout has been proven by its application in China. It can be believed that QCE grout has great economic efficiency and will give a push to develop grout material.

Jan 1, 1988