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By Tapp B. A

To date, few studies have been made regarding the energy requirements of the Australian mining and mineral processing industries. This paper indicates that these industries use a substantial proportion of the total Australian energy input (32.7% in 1971-72 and 36.10% in 1974-75). With the growth orientation of these industries, this input is likely to increase. Data shows that mining energy requirementE varied from 4.22% (of total Australian energy requirements) in 1971-72 to 4.16% in 1974-75. Energy requirements for the total mineral processing industries increased from 28.49% to 31.93% for the same period. The total estimated primary energy input varied from 22.56% to 25.2%, whilst indirect energy use, in the form of electricity increased from 10.16% to 10.66%; in the same period. Analysis of primary energy input data within the processing industries (1973/4) showed that the Iron and Steel Industry consumed 15.03% of the Australian total consumption, Non-Ferrous metals, 5.43%, Cement, 1.64%, and Refractories, 1.59%. In toto this represented 24.57% of the total

Jan 1, 1979

The Joint' Venture Method is a procedure for assessing the value of exploration properties, particularly those for which resources have yet to be delineated. It aims to convert the terms of an actual or synthetic joint venture into the equivalence of an arms- lengths cash transaction between a willing seller and a willing buyer. This paper sets out one approach to achieving that conversion. It discusses both simple and complex cases and gives some examples from both public and private documents. It also includes some case studies in which the Joint Venture Method of valuation can be compared with values derived for the same project using other methodologies including actual cash deals. The Method has failings in both mathematics and logic. However because it does reflect or simulate an arms-length deal which takes into account past exploration effort and expenditure and an assessment of prospectivity at a particular point in time, it is felt that it can provide a reasonable approximation of trade value or asset value of a prospect, particularly if used in conjunction with other methods.

Jan 1, 1994

By Boyes B. A, Haydon D. J

The Paddington project is a gold mining and processing operation located 35 km north of Kalgoorlie in the Eastern Goldfields region of Western Australia (Figure 1). The project, which is operated by Pancontinental Goldmining Areas Pty Ltd, treats 1.25 Mtpa of oxidised gold ore, derived mainly from open cuts adjacent to the plant, with minor tonnages from other pits in the region treated on a custom-milling basis. Gold is recovered using a conventional CIL process. The process raw water supply of 3 500 kUd is derived from the local groundwater system. Average salinity of the raw water is around 90 000 - 100 000 mg/L total dissolved solids. A small portion of the raw water is passed through a vacuum distillation desalination plant to produce the project's 200 kUd requirement for high quality water for potable use and gold recovery.

Jan 1, 1988

By U Briem, R Verreet

The level of wire rope technology used in mine hoisting applications has a significant effect on the overall efficiency of the hoisting system. This paper discusses the effect that a reduction in rope mass per unit length and an increase in rope breaking strength can have on rock skip capacity and hence mine shaft output. A 20 per cent reduction in rope mass per metre for a typical 48 mm hoisting rope, while maintaining the breaking strength, increases the skipÆs capacity by circa 30 per cent at a suspended rope length of 3000 m. Such gains in shaft output, without any significant changes to the shaft or winder design, can have major implications for the feasibility of future deep mine projects. The technical challenge for rope manufacturers is how to get rid of 20 to 30 per cent of the rope mass while keeping the breaking strength and modulus of elasticity of the whole rope constant. CASAR are currently developing steel wire rope constructions where the steel IWRC has been replaced with high strength, high modulus fibres such as Kevlar«, Spectra« and Dyneema«. One of the key aspects of such composite rope designs is to ensure equal load sharing between the different rope components, ie in proportion to their area. If there is a significant difference in modulus between the fibre core and the steel outer strands, the core may not carry its proper proportion of the load and the outer strands would be overloaded. Some technical aspects of the design of composite steel wire ropes are discussed. A design and operational issue that needs careful consideration is the safe non destructive testing (NDT) of composite ropes. Traditional magnetic NDT would only be capable of inspecting the steel wires. Techniques therefore need to be developed that would give operators a reliable indication of the condition of the load bearing fibre core. This paper also discusses possible solutions to this very important NDT question.

Jan 1, 2005

Minerals similar to the indicator minerals used in kimberlite exploration are widespread in the Cainozoic alkali basalts of north Queensland. Magnesian ilmenite, pyrope garnet, chrome diopside, chrome spinel, phlogopite and zircon were recovered from most of the localities examined. The occurrence of these minerals creates significant problems when indicator minerals are used for diamond exploration. Basaltic ilmenite is visually similar to kimberlitic ilmenite. Untransported grains are rounded and have pitted surfaces. Basaltic ilmenite grains often have exsolution lamellae and reaction rims of titanomagnetite. Although kimberlitic and basaltic ilmenite are chemically similar, basaltic ilmenite grains are usually less magnesian than their kimberlitic counterparts. Basaltic ilmenite contains very little Cr203. Pyrope garnet occurs as megacrysts and in a variety of xenolith lithologies in north Queensland basalts. Most basaltic garnet is Cr-poor and comparable with kimberlitic garnet from Groups 3 and 5 of Dawson and Stephens (1975). Wine-purple, chrome-bearing garnet is common in kimberlite but rare in basalt.

Jan 1, 1984

In mineral asset valuation the use of any valuation method requires the input of competent and independent technical professionals. A resource valuation must be as transparent as possible to allow others to assess the validity of their underlying assumptions. Materiality is a dominant factor in all valuations and a valuer should set out the basis for the subjective decisions made in this regard. Any valuation methodology must comply with the requirements of the law, practice notes and guidelines issued by the various relevant authorities and professional bodies. The valuation methodology chosen to value a mineral asset depends upon the amount of data available on that asset and the reliance that can be placed upon those data. Mineral assets generally fall into one of three broad categories, depending upon their state of development, ie whether they are at the exploration, development or operating stage. Naturally there are transition phases. Hence, there are ""Grass Roots"" Exploration Areas and Advanced Exploration Prospects; Pre-Development Projects and Developing Mines; and Operating Mines. The features of each of these mineral asset status categories are described, mainly in terms of the confidence in the contained identified Resources/ Reserves. The various subjective methodologies available for the valuation of ""Grass Roots"" Exploration Areas and Advanced Exploration Prospects -are specifically reviewed. The pitfalls in adopting a ""recipe"" approach are noted. It is the author's view that the Expected Value Method (based on the probability adjustment of the output of a Discounted Cash Flow/ Net Present Value model) has little application in the valuation of exploration mineral assets, so it is only briefly addressed. The methodologies reviewed are listed below. ò Multiple of Exploration Expenditure Method (expenditure based). ò Joint Venture Terms Method (expenditure based). ò Geoscience Rating Methods (eg Kilburn - area based). ò Comparable Market Value Method (real estate based). ò Rules of Thumb (eg $/Resource or production unit; % of in situ value). Some recent Prospectuses are used to provide examples of their misinterpretation and misapplication.

Jan 1, 1994

Parallel lenticular orebodies occurring at the C.S.A. mine of Cobar Mines Pty. Ltd. are mined by mechanized cut and fill stoping over the full strike length. Access is provided for each stope lift from an inclined drive adjacent to the orebody. Mobile drill jumbos mounting hydraulically-operated booms are used for drilling upholes which are subsequently charged with ANFO explosive.Close control of drilling has been found essential for good back conditions and to ensure optimum fragmentation.Broken ore is transported from the face to the main ore pass by rubber-tyred, diesel-powered, load-haul-dump units. Initially, the units trammed ore to the main pass via the incline drive. As the stopes advanced and the lead distances increased, stope passes were developed in the wall rock and raised concurrently with each stoping lift. The passes terminate in drawpoints and production loaders are used to transport ore from the drawpoints to the main ore pass system.Two parallel ore pass systems have been developed to cater for both copper and copper-zinc ores. These systems terminate above a 48 in. by 60 in. jaw crusher. The crushed ore is conveyed to a traversing rock box and thence to one of two crushed ore bins adjacent to the main hoisting shaft. A loading station conveyor is interlocked with the winder to provide automatic ore hoisting.All phases of ore handling have been mechanized as completely as possible. Results to date indicate this policy has been vindicated but highlight the need for tight operating control and close liaison between operating and maintenance personnel.

Jan 1, 1969

By Hood M

Rock cutting excavation technologies and particularly continuous excavation technologies, can offer benefits in the areas of reduced costs, higher revenue and increased safety in a variety of mining situations. Non-explosive rock excavation technologies for example, can deliver significant benefits in the areas of dilution and improved ground support (no overbreak). This paper is an attempt to focus on the development and future of alternative rock breaking technologies and to provide some insights as to why and how we should proceed in this direction. The market size for underground hard rock excavation technologies is examined. A short review of the evolution of various rock excavation technologies in terms of cost and production rate is given and a summary of the state-of-the-art technology is presented. Mechanical excavation technologies (TBM) have very high production rates compared to D&B and the gap is widening, however, they have not been successfully applied to mining applications. Operating costs for mechanical and D&B systems have been dropping over time, however, D&B costs are the lowest. Given the current state of knowledge it appears that with regard to hard rock underground metalliferous mining that R&D efforts should be focussed in the following areas - disc cutter tool development (materials and design; operation; presentation to the rock surface), hybrid cutting systems (consisting of water jets and disc cutters) and development of pressurised hole breakage technologies. It is also possible that two techniques known as the pulsed laser and pulsed water jets may have some potential. The generally agreed specifications for a widely applicable underground hard rock excavating machine are - disc cutter based, a minimum production rate of 100 t/h, be flexible, manoeuvrable and deployable, weight of less than 100 tonnes and be economically competitive with D&B in rocks over 150 MPa UCS. Such a machine would seriously challenge the position of conventional D&B in a wide range applications and provide some of the benefits of mechanisation and automation that the mining industry is pushing so hard for. However, technology developments in the D&B area are not static and hence the target is moving and is increasingly difficult to overtake.

Jan 1, 1995

By Sen G

An amount of explosives, whether it be cylindrical, spherical, etc in configuration, with a hollow cavity in one face or end is known as a hollow or shaped charge. When this charge is initiated, a focussing of explosive energy will occur within this cavity. This focussing, or concentration of detonation products creates an intense localised force greater than just the simple detonation of a conventional explosive, (without a hollow cavity). If this hollow cavity explosive is directed against a target material this concentrated force is capable of creating a deeper penetration than the same amount of explosive without the hollow cavity. If a metallic liner material is used in the hollow cavity, upon detonation of the explosive this liner will form into a high velocity penetrating jet. Depending on the explosive type and the liner material's configuration the jet tip can travel up to 10 km/s. Linear shaped charges were developed using the abovementioned shaped charge concept but instead of being formed about an axis, they are elongated and constructed along the principal axis. Therefore instead of creating a narrow circular penetration jet, it forms a thicker planar cutting jet ideal for linear cutting purposes. Using Linear Shaped Charges (LSC) for pre-splitting is expected to result in more accurate directional fracture propagation, while minimising lateral micro fractures in the surrounding rock mass which is required to remain undamaged.

Jan 1, 1995

By Hellsten K, Eshuys E

The best long-term approach to exploration involves the use of extensive quality data and the integration of many different factors, methods and techniques. The successful exploration manager needs to integrate people, area selection and exploration methods, with the use of descriptive and genetic geological models. Based on a syn-metamorphic genetic model for Archaean gold, successful exploration in Western Australia requires the integration of data on anomalous gold, alteration, lithology and structure. Many other parameters such as geophysics, geochemistry and regolith studies provide additional, indirect information that needs to be integrated into the overall exploration programme. Timely access to research findings and ability to integrate these into immediate exploration has contributed considerably to the success of the gold industry in Western Australia since 1980. Extensive and deeper drilling, and the ability of computers to handle the volume of data generated have enabled effective testing of many more geological targets.

Jan 1, 1996

By M Wortley, A Cantarutti, T Ozkocak

The estimation of the grinding mill charge weight is vital to ensure its efficient performance. Mill underloading or overloading can cause losses through decreased production or unplanned down time. Metso Minerals Process Technology Asia Pacific and South America (MMPT) has developed two systems for measuring mill load. The first is an acoustic system (SmartEarÖ) and the second is an online model-based charge estimation system. The aim of both systems is to facilitate better operation of grinding mills. SmartEarÖ performs analysis on an audio signal from the mill and allows each different frequency component to be viewed, analysed and used in process control for load estimation. By isolating different frequencies, SmartEarÖ can give an estimate of mill load. The online dynamic mill model uses measurable mill parameters (such as power) to predict the current total load. Kalman filtering can also be utilised to further increase the accuracy of the model. Both of MetsoÆs systems have been installed at BHP BillitonÆs Cannington mine to measure the load within their autogenous (AG) mill. In this paper, the methods of mill load estimation are reviewed and compared to the bearing pressure reading, which is the current method used by Cannington to control mill load. The redundant estimates of mill load provide increased confidence and consequently more robust grinding operation under a wide range of conditions.

Jan 1, 2008

By Hosking IA, Mirkov P

Among the solutions currently being considered for improving traffic flow in Sydney are the construction of major road tunnels, principally the Eastern Distributor Tunnels, leading from the end of the Cahill Expressway to Drivers Triangle and South of Taylor Square and the Sydney Harbour Tunnel, which incorporates sections of driven tunnel at the northern and southern sides of the harbour. The Eastern Distributor Tunnels, known as Stages 2 and 3 of the Eastern Distributor Scheme comprise: Stage 2 - A south bound two lane tunnel from north of William Street to Driver's Triangle. The southern end includes two Y junctions (locally 3 to 4 lane widths) with exits into South Dowling Street, Anzac Parade and Moore Park Road. Stage 3 - A north bound, two lane tunnel from Taylor Square to Palmer Street just north of William Street. Further details of the Eastern Distributor Tunnels are given in the paper by Baxter, Chappel and Fishburn (1986) which is included in this conference.

Jan 1, 1987

By Komosa T, Muir D. M

Adequate levels of dissolved oxygen are essential for efficient gold dissolu- tion. The actual levels in plantpuips can be seriously reduced by the presence of oxygen consuming reactive minerals, and reduced oxygen solubility in saline water. The rate of gold dissolution is then limited by oxygen availability rather than cyanide. Ion selective electrode dissolved oxygen meters can give an effective indication of the relative oxygen saturation, but they are not able to give meaningful values of dissolved oxygen in saline water, without custom calibration curves. When the dissolved oxygen concentration is rate limiting, the addition of oxygen or peroxide can improve gold leaching kinetics as well as reduce cyanide consumption.

Jan 1, 1991

The investment worth of a mineral deposit can only be realistically evaluated in relation to specific engineering design criteria, which fully details the proposed method of exploitation. These criteria have not in general been taken into serious consideration when leaseholders have reported reserves in the past. In fact, many "reserve" figures quoted are probably more correctly classified as geological resources. The industry now recognises that it is necessary to take into consideration not only grade and mill recovery factors, but also likely mining and processing costs as well as the current market price for the commodity. Once having estimated those costs which are applicable to the resource under study, they can be deducted from the gross inherent worth of the orebody to result in an estimate of the potential net revenue. Through a process of interactive trial mine designs and evaluation, reserves can be quantified to provide an estimate of the available recoverable economic reserves given a set of assumed cost and operational parameters. It follows then, that the available economic reserve recoverable from a given resource will vary from time-to-time as cost and price factors vary in response to changing technology and economic factors. A methodology is described which may be used to derive economic recoverable reserves based on a computerised model of the geological resource data and appropriate economic and operational cost algorithms. Examples are provided from both coal and gold studies to illustrate the impact of economic criteria on the magnitude of the reserve figure reported for each project.

Jan 1, 1987

Some of the major factors affecting ore reserve estimation in gold mines are discussed together with their impact on computational methods.The major priority in ore reserve estimation is to get sampling and geological problems resolved. Poor basic information cannot be remedied by mathematical methods.Generally the more complex a deposit becomes the greater the need for subjective assessment and the less applicable are more complex ore reserve methodologies.

Jan 1, 1984

There is very little in Australian mining law that sets out the rights of mining tenement and exploration licence holders as against other parties who wish to carry out ground or aerial surveillance over those areas.There have already been several legal actions arising out of this lack, and more can be expected as the public places more rigorous constraints on corporate and individual behaviour. Field personnel, who are mainly fairly junior and less experienced, are entitled to some guidance from the minerals industry, guidance which up to now appears to have been either lacking or covering such a wide range of standards from corporation to corporation as to be virtually useless.Because each State writes its own laws there is no consistency, and the laws generally are lagging behind developments in the industry. In particular, the practice of granting mining tenements for sporadic exploration, a practice that is a leftover from much earlier mining law, has dotted the Australian continent with unattended and unmarked or poorly marked tenements that are difficult to find but confer on the holder prior rights to the minerals under them. Entry onto those areas in most jurisdictions is an offence and their existence compromises the efforts of regional explorers.This clearly unsatisfactory situation requires remedying, which is the purpose of these proposals. A more systematic approach to the granting of reconnaissance, regional and detailed exploration, mining, and retention rights will eliminate much of the problem. For the rest, a code of practice needs to be adopted as soon as possible.

Jan 1, 1996

By L M. Lobato, J C. S Seoane, F J. Baars

The Carajßs Province presents several volcano-sedimentary sequences that comprise the Itacai·nas Supergroup. The rocks represent bimodal volcanism, and clastic and chemical sedimentation in relatively unstable basins subject to recurrent structural events with subsidence and volcanism. The Grpo Parß Group represents one of these sequences with mafic volcanic rocks that enclose discontinuous jaspilite lenses, with development of large high-grade orebodies (Fe >65 per cent). This unit is named the Carajßs Formation and presents peculiar characteristics compared to other iron districts in the world, thereby departing from the classic Lake Superior or Algoma iron formation types. Owing to the dense vegetation, lack of outcrops and harsh landscape, the structural analysis of the district can only be accomplished by combination of regional field work, detailed structural work on the open pits, and remotely sensed image interpretation, in this case Landsat ETM7, JERS-1 images and the SRTM digital terrane model. The regional trend of the several sequences of the area is approximately N-S and the structure is dominated by a flattened flexural fold system with axes moderately dipping WNW, intersected by several strike-slip faults subparallel to their axial plane. The Serra dos Carajßs represents an s-shaped synform-antiform pair, herein named the Carajßs Fold. This regional structure is partially disrupted by the Carajßs Shear Zone that divides it in the northern (Serra Norte) and the southern (Serra Sul) Ranges and also probably prepared the terrane with the development of pathways for mineralising hydrothermal fluids forming large high-grade massive iron bodies. Syntectonic granitic bodies played an important role in the structural evolution of the area as well. They caused localised ductile flattening deformation and thermal contact metamorphism in surrounding terranes. The Estrela pluton, for instance, was responsible for the discontinuity of the regional trend between the Serras do Rabo and Leste. The Carajßs Province is regionally the upper crustal product of a very shallowly eroded dome-and-keel geometry of Neo-Archaean volcano- sedimentary units intruded by syntectonic calc-alkaline intrusives and overlying pre-existing infracrustal rocks. The lithostructural data suggest continental-margin back-arc basin development and closure in an oblique collision belt, with N-S shallow crustal shortening, parallel to the inferred pre-existing strike of the stratigraphy.

Jan 1, 2005

By B Sno, P A. Cockburn, R C. West, C U. Jones

Clyde Materials Handling (CMH) and WorleyParsons have developed a concept for a flash furnace feed system using the specialist pneumatic conveying equipment expertise of CMH and the flash furnace process experience of WorleyParsons. CMH has developed a proprietary volumetric feeder (called a Rotofeed), which is extremely accurate and overcomes many of the problems inherent with loss-in-weight screw feeders and drag chain conveyors, previously regarded as state-of-the-art. Initial indications are that the Clyde-WorleyParsons feed system could deliver the following benefits to flash furnace operation: accurate pulseless delivery of feed material to the head of the burner leading to improved combustion performance and process stability; highly accurate split to the individual quadrants of a conventional burner tube, or provision of a smooth hollow curtain to a burner without guide vanes; decreased pressure pulsation in the furnace due to improved combustion control and performance; and decreased temperature fluctuations in the furnace due to improved combustion characteristics and hence reductions in refractory thermal stress and wear.

Jan 1, 2005

By Brent A. D, Olsen a. H, Mayfield P. L J, Grazier P. E

Concentrates produced from MnO2 and Fe203 ore fines have been targeted as potential feedstocks for direct metallurgical processing. Prereduction of pyrolusite-rich Mn02 sands to MnO has been investigated in batch and continuous experimental bubbling fluidised beds using CO-H2 reducing gas mixtures. This process has been found to produce a high grade feedstock suitable for smelting to ferroalloys or acid digestion for chemicals production. Similarly, production of highly metallised direct reduced iron (DRI) from hematite ore fines has also been investigated in batch bubbling bed reactors. Programs to characterise the reduction kinetics, fluidisation behaviour and defluidisation phenomena for both feedstocks are currently in progress to enable optimum process conditions to be determined.

Jan 1, 1995

The purposes of defining the mining environment for underground mass mining and the uses of characterisation data are outlined. The requirements for data in the areas of geology, surface and groundwater hydrology, topography and environmental constraints and geotechnical studies are identified. Emphasis is then placed on the collection and interpretation of geotechnical data for establishing the in situ stress regime and for rock mass characterisation. Methods used for diamond drilling, core logging, borehole logging, data analysis and presentation, rock mass modelling and rock mass classification are outlined. Finally, recent and potential advances in the state-of-the-art are identified in areas such as geophysical methods, measurement while drilling, computerised data collection and analysis, rock mass modelling, in situ stress measurement data presentation and interpretation, and some applications of rock mass characterisation data.

Jan 1, 2000