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The excavator selection process is quite complex due to the large number of influencing factors, many of these are variable and difficult to accurately define. The majority of mining companies prepare a tender of general specifications and suppliers will then match a product to those specifications. The mining company will then evaluate the tenders on the basis of the best available deal. In this paper, the importance of open pit excavator selection in terms of its impact on operating costs is analysed and discussed. A rigorous process for selection is then outlined.

Jan 1, 2003

By Potter OE

There appears to have been a swing away from the study of mathematics, the physical sciences, foreign languages and the classical humanities subjects by many students in high schools in Victoria. The same trend is believed to be occurring in other states as well. This has the direct result of many students entering tertiary studies inadequately prepared academically. This is particularly true in engineering and commerce. The position as far as postgraduate training in the areas of concern to the minerals industry is critical with almost no Australian nationals undertaking advanced technological studies.

Jan 1, 1981

Acid rock drainage (ARD) derived from sulphide oxidation and the associated metal leaching is the most significant environmental issue facing the mining industry today. Under given hydrological and biogeochemical conditions, the local geology and mineralogy largely control the formation of ARD. The involvement of a geologist is therefore essential in minesite ARD assessment and prevention. The relevant tasks that a mine geologist may undertake at three major phases of a mining project are briefly described. Additional knowledge that a mine geologist should acquire in order to achieve proficiency in ARD assessment is also suggested.

Jan 1, 1993

In the last 100 years, statistical sampling theory for particulate materials has developed to a stage where sampling systems can be confidently designed to provide assay results of known and controlled variance for a chosen time period. The two independent sources of sampling variance, namely intrinsic and distributional heterogeneity are defined and explained quantitatively. Intrinsic heterogeneity is characterised by the sampling constant for the material and distributional heterogeneity is quantified by the process steam variogram or covariance function. The means by which sampling systems can be designed to an accuracy specification is described.

Jan 1, 2002

By Lama RD

The paper outlines the development in the control of dust in Australia over the last 20 years. Factors influencing dust make at the faces are discussed. The effect of high production systems is analysed. Changes in dust standards and results of dust sampling on longwalls and continuous miner panels are given. Research conducted on air curtains and water infusion on dust control on longwall faces is presented along with recommendations for future research. It is found that both dust curtains and water infusion can cut dust mak by 50" each when applied separately.

Jan 1, 1988

By M DellÆAmico, K Vining

The iron blast furnace is the most widely used and efficient producer of liquid iron; however, emissions from sintering and coking cause environmental pressure for the integrated steel works. The combustion of coke fines (breeze) during sintering contributes to greenhouse gases (GHG) (eg carbon dioxide) and is a source of SOx and NOx emissions. Coking capacity is also constrained by environmental concerns and economic factors, such as increased coke consumption, and short supply is leading to high prices. Improved coking practices, which result in reduced production of fines, are also contributing to the tight availability of breeze for sintering. This combination of factors presents an opportunity to consider alternatives to coke as a fuel for sintering. CSIRO Minerals has been investigating the use of wood biomass/char as a substitute for coke during sintering. Wood biomass, or char produced from it, is an attractive carbon source as carbon dioxide liberated during combustion can be sequestered back into growing biomass. It has great potential to reduce the emissions from integrated steelworks and improve their environmental acceptability. Harvested biomass/char is also a renewable and sustainable resource and can be integrated with good land management practices such as remediation of salinity affected land. Weeds, especially woody weeds, can also be used as a source of biomass for charcoal, and integrating char production with weed management can help address a pressing environmental issue in Australia. Previous reported preliminary testwork indicated that the use of Red Gum char as a replacement for coke resulted in a product sinter of comparable quality, improvements in productivity and significant reductions in SOx and NOx emissions. In the latest testwork, CSIRO has examined the properties of a range of potential charcoals, and has conducted a further series of granulation and small-scale sintering trials with them in simulated Japanese Steel Mill iron ore blends. Sinter fuels characterised and evaluated include industry sourced coke breeze, commercially available wood char and a charcoal from prickly acacia (acacia nilotica). Prickly acacia has been declared a noxious weed, is widespread in Australia, and is classified as a æWeed of National SignificanceÆ. The results presented in this paper support the notion that charcoal outperforms coke in many aspects of iron ore sintering and factoring in environmental considerations makes the switch to charcoal even more favourable.

Jan 1, 2005

Diversity is a key strength for Western Mining Corporation. An international corporation with assets of about $A10 billion, WMC is engaged in both mining and downstream processing of minerals including nickel, gold, alumina, copper and talc, as well as having interests in oil and gas production and agricultural fertiliser. The company is focusing on several core commodities that will maintain its strength in the years ahead. Although most current mineral assets are within Australia, it plans to have 25 per cent of its operations off-shore by the turn of the century, and be a major producer in at least six core commodities. WMC's strategic and management focus has shifted from a regional approach to a commodity focus so that it can more readily cater for different markets with differing sensitivities. This document is an ABSTRACT ONLY - no paper was published for this presentation

Jan 1, 1996

Explosives have been an important tool for unlocking minearl wealth from the earth's crust for several countries. In'the past, innovation in explosives technology, spurred on by industry needs has assisted the Mining Industry to improve productivity and reduce costs. A symbolic relationship exists between Explosives and Mining. Australia has vast mineral wealth. Our Mining Industry is of major importance to the Economy., The value of mineral produc- tion in 1987 was $25 million or 10% of GDP. Australian Mining is a business depending on international markets. The Mining Industry is our leading export earner, generating 44% of all export income. 60% of mineral production is exported. About half of these minerals are extracted using explosives. Explosives rank as one of the top three consumable expenditures for a mine. For example: A major open-cut iron or coal mine can spend $6 million dollar per annum on explosives.

Jan 1, 1988

To grow a mining company today is seen to be challenged by the reduced interest in resources companies by the financial markets, the complexity of native title and a somewhat depressed commodity cycle. However, the opportunity to grow production and sales in a mining company are as numerous as they have ever been. It is the challenge of growing significant shareholder value that is difficult. The distinction between growth in æcompany sizeÆ and growth in æshareholder valueÆ is an important distinction upon which some resource companies are now firmly focussed. The equity market/commodity market cycle can provide windows of opportunity to consolidate and expand a company for the benefit of shareholders. These benefits may not be reflected until more buoyant equity markets return but, as the cycle turns, as it surely will, those with the foresight to position themselves may be richly rewarded.

Jan 1, 2000

By P Murthy, Z Guan, P Townson

In this paper, we introduce a methodology to optimise mining equipment operation in terms of the conflicting concerns of productivity and availability. We also introduce the concept of damage points and equipment dutymeters. These provide the mine management with tools to monitor the success of such optimisation. Since we have quoted the results of an on-going Australian Coal Association Research Program (ACARP) project, the apparent focus of this article is on draglines. However, the concept is equally applicable to other equipment. Mining is the type of business that requires a large investment in capital infrastructure and equipment to produce a product that is sold at a relatively low unit cost. In such a business, the key to competitiveness lies in achieving the full realisation of capital investment ie sustained production at high levels. Some of the concepts outlined in this paper are essential components of this picture.

Jan 1, 2000

Exploration by Cyprus Minerals Australia Company (formerly Amoco Minerals) has successfully outlined significant Au-(Cu) mineralisation at Starra, 150 kilometres south-east of Mt. Isa. Mineralisation is stratabound and localized in deformed and metamorphosed ironstones (B.I.F?) and iron-oxide bearing schists of the mid-Proterozoic Staveley Formation. Over 90% of the presently outlined potential ore occurs in 4 discrete zones within a strike length of 3.5 kilometres. The inferred geological resource in these zones is approximately 6 million tonnes grading 5 grams per tonne gold and 2% copper. Roughly half of this is open-pittable, but more rigidly applied mining criteria will probably reduce the exploitable tonnage. Detailed infill drilling is in progress and a pre-feasibility study has commenced. The joint venture partners, Cyprus Minerals (75%) and Elders Resources (25%) expect to make a development decision by the end of this year.

Jan 1, 1986

Those involved in managing risk today are asking various questions: why is it so frustrating to discuss æriskÆ with communities? why do consultative processes around æriskÆ get more and more complex? where is all this going to end? These questions will be addressed by examining how our understanding of risk has changed from one based on biophysical hazard to a broader view that includes social and cultural factors. There is evidence to suggest that we are living in a ærisk societyÆ, where the goal of æsafetyÆ has replaced that of equality in a class based society. The global mining industry operates within this complex and politicised environment. The very meaning of ædevelopmentÆ has broadened from the narrow economic vision to include the social and environmental factors which make up æSustainable DevelopmentÆ. Corporate accountability now extends beyond traditional shareholders to wide groups of stakeholders. The mining industry is developing responses which look beyond traditional technocratic methods. At the industry level these responses have included the recent Mining Minerals and Sustainable Development global and regional reports It has proven challenging and difficult to operationalise these new understandings at the company level and it is time to look at the bigger picture.

Jan 1, 2003

By I Lipton

Dilution and ore loss have an important bearing on the success of open pit mining projects. Their impacts on production costs, revenues and production rate require that they are correctly modelled in the long-term mine plan. The estimation of dilution and ore loss is therefore an essential part of any Ore Reserve estimate or mine schedule. Large open pit mines are driven by the economies of scale that are achieved at the cost of less selectivity in the discrimination of ore and waste. Planning for these mines is facilitated by the use of block models for mine design, scheduling and the conversion of Mineral Resources into Ore Reserves. This paper reviews various approaches to the estimation of dilution and ore loss, as implemented in computer block models. In the case of orebodies with well-defined sharp boundaries, rather than irregular stockwork mineralisation, the geological interpretation is a critical factor. Variability in the geometry of orebodies is common within large open pits and must be taken into account when estimating dilution and ore loss. A method of regularisation, controlled by the wireframed geological model, is demonstrated, using examples from large open pit stratiform copper and magnetite deposits. This can be carried out without special computer software modules.

Jan 1, 2007

By R E. Hobbs, O Grabandt, C Das

Mine hoisting is carried out from depths of up to 4 km. At extreme depths, the ropes are so heavy that a large part of their capacity is employed in lifting themselves. Consequently, deep mines have an intermediate winding station. Even at lesser depths, the weight of steel wire rope reduces the possible payload. Of course, steel wire ropes have, over the years, demonstrated exceptional reliability and acceptable lifetimes. The use of steel is supported by well established operating rules and sound NDT methods. However, lightweight ropes made from synthetic fibres could be of great benefit to the industry, with the prospect of eliminating two-stage winding and substantially increasing the payload. Initial tests, in cycling over sheaves, have demonstrated that an aramid co-polymer fibre, Technora« is a potential candidate for this type of service. This paper presents results of testing carried out on aramid co-polymer and other synthetic fibre ropes. These results hold out the prospect of exceptionally long lives. Possible NDT methods are explored including optical fibres with optical time domain reflectometry or with Brillouin scattering, plus a method based on carbon fibre continuity. The introduction of aramid co-polymer ropes will require extensive testing and a program is proposed in the format of a Joint Industry Project.

Jan 1, 2005

Future hard rock mining will gradually move towards complete mechanisation which lends itself to remote control and ultimately to robotic mining. This will require different technical inputs into mining engineering and one of these is in the area of rock'mechanics. Traditional hard rock mining has had little rock mechanics input. Problems arising from high stresses and poor ground conditions have in most cases be remedied after they occurred, in the worst case by abandoning a particular stope or area and starting elsewhere. In a fully mechanised remote or robotic mining situation the financial penalty for such an approach could be severe, as a major part of the production costs will be in the development and the equipment. It is therefore imperative that a complete rock mechanics feasibility study is undertaken before an area is set up for robot mining and that a continuous stability monitoring system is installed that will predict rock behaviour well in advance of mining, such that the necessary ground control measures can be implemented without impeding the continuity of mining. This system will utilise already existing instrumentation such as extensometers and stress cells, and possibly additional improved instrumentation which has to be developed for this particular Application.

Jan 1, 1986

By R M. Hough, G Duclaux, M A. Pearce, M F. Gazley

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Microcharacterisation, such as that described in this paper, provides understanding of a mineral system at multiple scales, and understanding microscale variations is the key to understanding the large-scale variations in a mineral system. More than 50 high-grade lode samples from across Plutonic Gold Mine (Plutonic), Marymia Inlier, Western Australia were analysed by a variety of techniques, including micro X-ray fluorescence (µXRF) mapping, micro X-ray computed tomography (µCT), scanning electron microscopy (SEM), field emission gun SEM, electron back-scatter detector (EBSD), proton-induced X-ray emission microprobe and synchrotron XRF mapping. These data demonstrate that competency contrasts are the key to governing the location of Au mineralisation at Plutonic. Micro CT imaging of high-grade samples shows the Au filling in voids and pore-space in the rock, after having travelled along more permeable layers and already existing or reaction-induced pores formed during hydrothermal circulation. Using 3D visualisation, the Au is seen to form a connected network that appears undisturbed at the scale of the samples, and a high-grade Au deposition event was one of the last events to affect the rock. This interpretation is supported by SEM analyses on high-grade samples that reveal calc-silicate (epidote-clinozoisite) alteration that is not present in lower Au grade samples, which are typically dominated by potassic alteration, and that sulfides are typically less abundant close to the Au. The replacement of biotite by chlorite is an alteration associated with the high-grade Au-mineralising fluid. Gold is coarsest where Au particles are located on the margins of minerals, typically sulfide and quartz grains, suggesting the importance of rheological contrast at the microscale. Furthermore, EBSD data reveals that Au is undeformed and overprints peak metamorphic and retrograde minerals. Data confirm recent deposit-scale observations, suggesting that deposition of high-grade, visible Au was related to a hydrothermal fluid circulation event late in the geological history of Plutonic.CITATION:Gazley, M F, Duclaux, G, Fisher, L A, Hough, R M and Pearce, M A, 2015. High-resolution characterisation of gold mineralisation at Plutonic Gold Mine, Western Australia – evidence for the late-stage deposition of high-grade gold , in Proceedings PACRIM 2015 Congress, pp 51–58 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

In the pursuit of commercial solutions for environmental issues, individual problems are often identified, considered and resolved in isolation from other environmental matters and always at the end of the cycle û after the problem has been created. Inter-relationships are neglected if they are not seen to obviously impact on a specific problem and the issue at hand is plucked from the environmental landscape and dealt with in total isolation to all else. In a Zero Waste approach to environmental matters, all outputs are pursued as potential inputs. Industrial processes are viewed as a variation on natureÆs theme and opportunity pursued above all else. When viewed from this perspective, industry appears to have forgotten its origins. It has forgotten that it is principally about people. The juggernaut of global trade has forgotten that it is a small part of a big landscape and that its principal participants, people, cannot exist without healthy soil. Commercial activity in all parts of the world relies heavily on the ability of agriculture to produce the necessary inputs for industrial production. The care and nurturing of our soils is fundamental, not only to the survival of humanity, but also to the economic systems that support that humanity and to the industry which profits by it. Actual levels of domestic recycling in many countries around the world seldom reflect the 90 plus per cent desire to recycle recorded in surveys conducted by local authorities in almost every country. If the desire to recycle is far removed from the end result, why is it that the systems provided are so ineffective? It is obvious that what we do need is a recycling system that both engages and rewards the participant and stimulates the innate desire to support the environment. A recent trial in New South Wales, Australia, demonstrated that by giving individual households credits for recycling organic wastes, not only will contamination levels fall dramatically, but increased yields, improved soil structure, improved land values, reduced fertiliser costs and increased water use efficiency give the farmer good economic reasons for purchasing and applying quality composted product. By underpinning and securing the agricultural community, we secure the future of industry. The æCity to SoilÆ project linked the economic on-farm benefits of compost use with reduced contamination through the provision of rewards paid for by the purchase of product by the farmer.

Jan 1, 2006

By H Holmstr÷m, A Widerlund, M Lindvall

At the Kristineberg mine in northern Sweden sulfide-rich, poorly buffered tailings have been deposited in five impoundments located along a valley. The tailings area has been remediated by applying a combination of till cover and flooding. A new method that has been applied to parts of the tailings area is to raise the groundwater table to saturate the tailings. By increasing pH by liming, thereby reducing metal mobility, a water-covered downstream impoundment is functioning as a trap for metals released from the till-covered impoundments upstream. In this paper the efficiency of the system approach used at Kristineberg is evaluated. Progressive changes of water quality from groundwater in the upstream till-covered impoundments via surface streams within the pond system to the water in the flooded downstream pond and its outlet are described. The results show that the system approach used in the design of the remediation programme of the tailings works as planned. The sulfide oxidation rate has decreased in the till-covered impoundments, and, as predicted, there is an out-flush of old weathering products which will continue for at least five years before equilibrium is reached. The groundwater in the till-covered impoundments has high concentrations of Fe, S, Mg and Zn, but the concentrations of metals such as Cu, Cd and Pb are much lower than before the till cover was applied. The limed pond is an efficient metal trap, with concentrations as high as 2.76 per cent Zn and 0.28 per cent Cu in the calcite-gypsum sludge developed on the tailings. The outlet from the flooded pond, and thus from the whole mining area, releases small amounts of metals to the recipient in comparison to the amounts that are in movement within the mining area. During the period May to November, 13 kg dissolved Zn and 111 kg particulate Zn was released to the recipient, whereas a total of 27 000 kg was transported by surface water within the impoundment system during the same period. The results from Kristineberg show that when planning remediation of complex mining areas, it is useful to adopt a system approach in which different methods are used on different parts of the area along the flow path of the drainage water, whereas flooding of the downstream pond is the key to the performance of the entire system.

Jan 1, 2003

By Bogar D. V

Often dewatering of coal tailings is inhibited by the presence of clays, making it difficult to obtain a high concentration, handleable coal tailings. The net result can be a low concentration, chocolate mousse-like tailings which poses significant sedimentation problems in a tailings dam and represents a significant environmental problem. This paper examines the coal tailings from a Hunter Valley colliery where the tailings properties are influenced significantly by the presence of montmorillonite clay. The influence of the calcium ion on the rheology and sedimentation/compression behaviour of coal tailings . containing montmorillonite already dispersed in water was investigated and revealed that very little improvement in the properties is achieved through the coagulation. The preliminary investigations also indicated that the properties of the tailings were dominated by the presence of the montmorillonite clay. Thus investigations were carried out on the clay alone in water. Investigations into the effect of dispersing samples of the clay alone in water and then coagulating with calcium compared with dispersing the clay directly into calcium ion solutions at the same calcium concentration showed huge improvements in the rheology, compressibility, sedimentation rates and sediment solids concentrations for the second dispersion method, which can be called controlled dispersion. The sediment volume fraction solids improved by more than a factor of two by controlling the dispersion of the clay. The reason for the improved properties lies in the suppression of the initial swelling of the clay, which is initially in the sodium form, thus maintaining the parallel orientation of the platelets that is present before wetting. While swelling is being suppressed, ion exchange occurs with the calcium which results in permanent swelling suppression. In the uncontrolled dispersion case where swelling is uninhibited, the clay is allowed to break up and despite the powerful coagulating nature of the calcium ion, the random orientation of the high aspect ratio clay platelets inhibits effective coagulation. Results indicate that the initial electrolyte concentration of the washwater in a coal washery is the critical factor controlling the dewaterability of clay tailings and the handleability of the dewatered product rather than the actual act of coagulating with the calcium ion. The results presented are of clear practical significance and indicate how coal tailings problems where clay dominates the rheology can be improved considerably by knowledge of the surface chemistry.

Jan 1, 1995

By A S. M A Haseeb

Zircon is the second in abundance among the heavy minerals occurring in the beach sand along the coastal belt of Bangladesh. In this study a detailed characterisation of Bangladesh zircon extracted at the pilot plant of the Bangladesh Atomic Energy Commission at CoxÆs Bazar has been attempted using chemical analysis, X-ray diffraction and optical microscopy. From the chemical analysis it is found that Bangladesh zircon has a purity of 95.88 per cent. The main impurity in Bangladesh zircon is titanium oxide (3.01 per cent). This is followed by iron oxide (0.42 per cent). A number of other oxides are also found. Microscopic study revealed that Bangladesh zircon has an elongated, prismatic shape with pyramidal termination in about half of the grains while the rest are more or less rounded. Some fractured and irregular grains are also found. Bulk sample of Bangladesh zircon in the as-received condition shows a yellowish brown color. However, individual zircon grains are seen to be almost colourless and transparent under polarised light. XRD study confirmed good crystallinity in the sample. Under the microscope it is found that zircon grains constitute 94 per cent while total impurities amount to six per cent in Bangladesh zircon. This result agrees fairly well with the chemical analysis results. Microscopic study identifies oxides of titanium (both rutile and ilmenite) to be the main impurity, in conformity with the findings of chemical analysis. Further, monazite was also identified as an impurity under the microscope. An iron bearing coating is also found on a few zircon grains. Most of the impurities found in Bangladesh zircon exist as discrete minerals.

Jan 1, 2000