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Synthetic seismograms of reflectivity method and some field records available are studied to detect the amplitude anomalies at the interface of the gaothermal reservoir the gas and/or oil boundary, and the underground tunnel. The first arrival of PO wave on the P-SV record are weak and emergent while those of P wave only rotated with respect to an incident angle are clear. This can, be explained by means of the energy loss of P-SV wave conversion. The primary reflections of P waves about depth fade away as compared to SH waves which do not perform any conversion, although they hold high attenuation in the fully saturated fluid layers. Reflection of comparable strength is present at the P-wave and S-wave... boundaries, but gas-saturated zones correlating with P wave bright spots do not show equivalent attenuation anomalies. Thus the comparative technique of P-SV wave and SI i wave records is very useful to indicate the strong amplitude anomalies at the boundaries of sealing targets.

Jan 1, 1990

By L Cain, C Every, S Mirlatifi, J Ashley

This paper presents a geographic information system (GIS) based method for the prediction of ground movement and the associated impact on existing buildings and structures due to tunnelling in the North West Rail Link (NWRL) project. The NWRL is a priority rail infrastructure project for the New South Wales (NSW) Government and includes 15 km of twin tunnels between Bella Vista and Epping, which will be Australia’s longest rail tunnels. The NWRL tunnels will be constructed in an urban environment where the prediction of ground movements induced by tunnelling and the associated impacts to existing structures must be assessed in the early design stages of the project. An assessment process was developed using GIS able to respond to design changes.An iterative GIS analysis methodology was developed to generate ground settlement contours and identify impacted buildings and structures in response to multiple changes in tunnel alignment during design development stages. The GIS analysis undertook to rapidly provide detailed and accurate parameter information including tunnel depth from surface, tunnel separation, diameter and sample point proximity to the tunnel and assess ground movement contours along the project alignment. Determination of the ground surface settlements were based on empirical methods proposed by Peck (1969) and Mair (1993). The control parameters and the relationship between damage categories and risk classifications for impact assessment were based on Burland, Broms and de Mello (1977), Rankin (1988) and Boscardin and Cording (1989) methods.The GIS-based ground movement impact assessment approach adopted for the NWRL project demonstrates an efficient, iterative and robust approach and could provide an initial framework for other similar tunnelling projects where rapid design changes and early understanding of tunnelling impacts are required to bring greatest benefit to all stakeholders.CITATION:Mirlatifi, S, Cain, L, Ashley, J and Every, C, 2014. An iterative geographic information system based approach for the assessment of tunnelling impact to existing buildings and structures, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 647–652 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By N Steenkamp, L Furstenberg, W Cele, M Richter

Managing productivity and improving efficiency for a healthy return on capital employed have become key mining industry strategies under prevailing tough global market conditions. However, achieving this in a multisystem environment such as a mining operation can be daunting. The field of discrete event simulation offers some relief, giving engineering teams insight into multivariable systems and stochastic processes. It allows for integrated system thinking and domain expertise to be woven into project thinking fibre. Directed system optimisation and therefore improved efficiency becomes possible. Furthermore, capital discipline accrues from optimal upgrade investments. This paper illustrates the practical application of this approach by reviewing a typical case study for a direct shipping iron ore operation. Dynamic simulation was used to establish maximum processing plant capacity under varying material characteristics and identify capital-efficient upgrades for increasing production.The study started with descriptive statistical analysis of existing data. Discrete equipment and system capacities were defined, followed by static plant mass balance calculations to establish bottlenecks and overall static capacity. Equipment ‘uptime’ and ‘downtime’ analyses established system and overall plant availability and utilisation. From this information, a dynamic simulation model could then be developed and initially calibrated against actual plant performance to verify its robustness. Once confirmed to accurately represent existing plant dynamics, system capacity response to variable changes could be tested to ultimately determine maximum plant capacity. Additionally, plant optimisation was incorporated to arrive at optimal upgrade points. Maximum capacity and necessary upgrades were established as a function primarily of feed size distribution. Additionally, the interfacing effects of rehandling feed material to the final product grade and potentially to life-of-mine were established as important outcomes. The results of the study illustrate the value of using dynamic simulation models to realistically and cost-effectively increase throughput.CITATION:Cele, W, Furstenberg, L, Richter, M and Steenkamp, N, 2015. Capacity evaluation of iron ore processing facilities utilising dynamic simulations, in Proceedings Iron Ore 2015, pp 597–604 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By J Kinal, P Steinier

A considerable volume of work exists in the literature examining the electrochemical interactions between grinding media and sulfide minerals. Broadly, most sulfide minerals are more noble than forged steel grinding media used during comminution, therefore a galvanic couple between the media and the sulfide mineral(s) exists, which increases the corrosion rate of the grinding media. The corrosion products of the grinding media, iron oxy-hydroxide species, invariably precipitate on to the surfaces of the sulfide minerals thereby affecting their floatability. This paper explores the science behind these corrosion reactions, and provides an explanation of their impact on the pulp chemistry of sulfide mineral slurries and subsequent flotation behaviour. A number of laboratory and plant case studies are used to illustrate the benefits of changing to a more inert grinding media.

Jan 1, 2005

The importance of proper planning, preparation, and execution of a steady state sampling campaign for metallurgical plant assessment must not be underestimated. Careful planning can increase the amount and reliability of information from an optimum number of samples and fully utilize available plant data. It requires specification of the data required, determination of run duration sampling frequency, the selection, modification and testing of sample points and cutters, as well as organisation and briefing of plant and sampling personnel. Preparation immediately prior to sampling, the conduct of the sampling campaign itself and procedures to handle the collected samples and information are discussed. Cutter design, fabrication and use are described in detail, and typical sampling situations, for ball mills, classifiers, pipes, launders, flotation cells and thickeners are considered individually. Measurement of pulp flow rate can often resolve difficult mass balance problems, and discussion of convenient techniques is included.

Jan 1, 1976

Copper heap leaching involves both the simultaneous and sequential leaching of very large tonnages of ore over long periods of time. It is not unusual to be leaching three or four million tonnes over periods of 12 to 18 months. As a consequenc

Jan 1, 1998

The need for formalised geotechnical reporting has not been fully explored at many operations. With the continuing need to provide safer and more efficient workplaces, the requirement for good geotechnical reporting systems (as with other reporting systems) has become of greater importance.Historically, the risk from rockfalls has been the largest cause of fatal injuries in the underground mining industry. The response of the ground to mining is generally poorly documented at many mines. At Olympic Dam, it was found that the existing corporate hazard and incident reporting (HIR) procedure did not record enough specifics about geotechnical issues. A separate and more specific geotechnical reporting process was set up to address this problem.This paper examines the role that geotechnical reporting plays at the WMC Resources Olympic Dam Mine; from reporting and rectifying day-to-day geotechnical issues that affect the operation to documenting and analysing longer term trends.

Jan 1, 2004

By Nichol R

- PART A The Hoppers Crossing Pumping Station is one of the principal components of the Western Trunk Sewer Project which replaces the 90 year old Main Outfall Sewer and will convey 60% of Melbourne's sewage flow from Brooklyn to the Board's Farm at

Jan 1, 1987

By S Hughes

The smelting of concentrates and secondary materials has been subject to increasing challenges in recent years due to declining grades of feed materials, increasing impurity levels and ever more stringent environmental regulations. In addition there has been a growing focus on maximising the efficiency of energy usage and recovery of values. New opportunities have been created with rising metals prices and improved systems for the collection of secondary materials, giving rise to a need for more flexible process solutions.This paper focuses on a number of specific cases where a process solution has been developed using the Outotec« Ausmelt Process to meet particular feed material challenges and overcome limitations inherent when employing traditional pyrometallurgical processes.The first case involves the development and commercial implementation of a smelting process to recover values from zinc smelting residues typically deposited into dams as a waste product. The second case describes the application of the Ausmelt process for the smelting and converting of secondary copper feed materials, including e-waste. These materials contain a wide range of metals and plastics and need to be processed appropriately to maximise the recovery of values whilst avoiding environmental problems. The third case study covers the smelting of nickel concentrates containing elevated magnesia levels as well as nickel bearing catalysts with high alumina content, neither of which can be readily processed when employing traditional pyrometallurgical technologies. CITATION:Hughes, S, 2013. Pyrometallurgical process solutions for complex raw materials, in Proceedings MetPlant 2013 , pp 519-530 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

The future of the United States (US) mining industry will be affected greatly by recent coal mining disasters. These have resulted in new legislation which will have an impact on mining economic costs as well safety and health of miners. This paper discusses the changes that new legislation and regulations are making to the industry and current research that is producing technologies to make mining safer and will likely impact the future of mining.

Jan 1, 2008

By Artone E

screening equipment installed in e Hamersley Iron operation is described, and tails of operating parameters and screening - Iia in use are given. Tests were carried out on full-size reens in the operating plants to study the Meets of mat aperture size, feed size distri 1,ution, feed rate, screen speed and throw, angle of inclination, and feed moisture content n screen performance. Sampling equipment was signed so that undersize samples could be htained from various locations along the length of the screen, thus providing information pout the quantity and size of particles passing òhro gh the screen at any point. Conclusions derived from the testwork and relevance of these to the Hamersley Iron aeration are discussed.

Jan 1, 1984

Synthetic hollow microspheres have demonstrated reliable sensitization and detonation characteristics in industrial explosives for almost two decades. During that time, water gel formulations and use conditions have changed. The introduction of emulsion explosives has also dictated technical improvements in microsphere sensitizers. In contrast to microspheres, gassing or other sensitizing techniques often cannot satisfy the manufacturing and blasting characteristics required of today's explosives. This paper discusses the sensitizing properties of microspheres, formulating guidelines and quality considerations. Packaging, sampling, transfer, metering, mixing and pumping information is also provided.

Jan 1, 1990

By Caivin JS, Freeman CJ

The Fairbanks Mining District in central Alaska was discovered in 1902 and since then approximately 7.5 million troy oz of placer gold, 250,000 troy oz of lode gold, and several thousand short tons of antimony and tungsten hap been produced from an area of about 1000 km . Historic lode production was from high grade gold-quartz veins that averaged 1.3 OPT free milling gold. Five main types of mineral deposits' are recognized in the district. I. Conformable, stratabound volcanogenic zinc, antimony, lead, and copper sulfides in places containing gold, silver and tungsten in bimodal metavoleanics (Cleary Sequence). II. Complex precious metal-bearing lead sulfosalt-quartz veins in Cretaceous granitic intrusives. III. Tungsten skarns adjacent to granitic intrusives. IV. Gold-bearing polymetallic sulfide-quartz veins crosscutting metavolcanics and metasedimentary units of the Cleary Sequence. V. Antimony-bearing gash veins along axial plane shears in various lithologies of the Cleary Sequence. Type I and Type IV mineral occurrences are currently being evaluated as low. grade bulk tonnage (target model 16-20 'million tons of 0.05 to 0.15 OPT)'and high grade moderate tonnage (target model 0.5 to 2.5 million tons of 0.5 OPT) gold deposits. The host rocks for Type I mineralization occur over a 30 km strike length and are at least 300 meters thick. Stratigraphic, structural, fluid inclusion, and isotopic data suggest that the Type IV mineralization is related to remobilization of Type I

Jan 1, 1987

By D M. Brady

Underground coal mines in Australia have embraced the use of various inertisation techniques both proactively and reactively. The use of such techniques can have a significant influence on ratios and trends used to monitor the status of the underground environment. Whilst control strategies should never be ignored in favour of preserving the integrity of ratios, the influence and significance of the changes likely to be seen should be anticipated and understood for reliable interpretation of the situation. This paper looks at the influence inertisation techniques can have on results and subsequent interpretation.CITATION:Brady, D M, 2013. The influence of inertisation techniques on gas interpretation, in Proceedings The Australian Mine Ventilation Conference , pp 259-264 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 1, 2013

By Watt KL

Chemical anchors for use in rock bolting have been produced in Australia under licence for several years. These anchors are alternatives to the more normally used mechanical anchors and give improved anchorage strengths under some conditions, although at greater cost. Considerable development during this time has resulted in an improved sausage-type chemical anchor more competitive in price, to such an extent that its use is increasing markedly. Particular-improvements allow load application up to the strength of the bolt within 2 min, reduction in cost, self-extinguishing features in the resin, improvements in manufacturing techniques, and an improved water- insensitive casing. At the same time, smaller bolt sizes have allowed reduction in resin volumes with consequent cost reduction. At this stage several aspects remain to be improved, particularly specialty anchors for specific purposes and Packaging.

Jan 1, 1971

Scale build-up in titanium palladium alloy spent electrolyte heat exchangers in the residue treatment plant commissioned at Risdon, Tasmania in 1971 was shown to be a mixture of manganese dioxide and anhydrite (CaSO4). The manganese dioxide was deposited as a result of thermal decomposition of permanganate ions present in the spent electrolyte. It was shown that deposition of manganese dioxide and associated anhydrite scale could be prevented by prior reduction of permanganate ions to the manganous (Mn++) state by the addition of ferrous ions. In the plant this was conveniently accomplished by injecting into the inlet line to the heat exchangers sufficient zinc plant solution containing ferrous sulfate to decolourise the spent electrolyte. This action prevented deposition of such scale for another 21 years, until the heaters were finally decommissioned in March 1992. Measurements indicated that addition of the reducing solution lowered the anodic potential of the titanium alloy by 200 - 300 mV (depending on the solution resistance), but that it was still +300 to 400 mV with respect to a standard calomel electrode. It was shown that, if necessary, a small impressed current could be applied to provide anodic protection. Before scale deposition was overcome by the addition of ferrous sulfate solution, badly scaled heat exchangers were cleaned by recirculating a solution of hydrogen peroxide in spent electrolyte or dilute aqueous sulfuric acid, after laboratory testing of a variety of possible solvents for the scale. Corrosion tests indicated that attack on the titanium alloy by the acidic peroxide cleaning solution was insignificant.

Jan 1, 2005

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

By Vink L, Johnson N. W, Mackenzie J, Young M. F, Johnston M, Landmark V

The influence of ore textures on metallurgical behaviour is poorly understood for most ores. An alternative method for characterising ore textures and for determining the resulting implications on ore processing has been developed for the Geor

Jan 1, 1998

Subsurface information from the "Upper Coal Measures" of the Sydney Basin is interpreted by means of structure contour maps, isopach maps and geological cross- sections. Particular reference is made to recent coal drilling operations by the New South Wales Department of Mines. The study is restricted to the onshore portion of the Sydney Basin.

Jan 1, 1972

By F Grobler

Many projects fail because project performance in unfavourable economic conditions was not anticipated at the investment decision stage. This type of failure may have been avoided through the selection of a strategy that enables the project to perform well under a range of possible future economic conditions (a ærobustÆ strategy); rather than an æoptimalÆ strategy for expected future conditions that will never eventuate. This paper describes a method of rapidly generating mine plans for a number of project strategies, and then evaluating it against a representative range of equally likely economic conditions. The key performance indicators derived for each strategy are the mean value and the distribution of values (variance). A prudent investor will identify prospective strategies not only on the merit of highest mean values (as a proxy for economic reward), but also on the probability of not meeting specified investment hurdles (a proxy for risk). A robust strategy will achieve its financial objective even under adverse economic variations. This paper focuses on the effect of commodity price uncertainty; particularly around the choice of mining and processing capacity levels. Results from enumerating 2000 prices scenarios against 63 strategy combinations show how processing and mining capacity can be manipulated to manage the risk-reward trade-off.

Sep 26, 2011