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By Goode RA

It is-assumed that a pipeline system is economically justified as a means of transportation.. The terms "True Life" and "Economic Design Life" are defined. The most usual design alternatives to be considered from both physical and economic -viewpoints are listed and a summary is given of the main factors to be costed in assessing the relative economics of each alternative. A brief statement of the recor mended method af economic. assessment is given and an example is included. The paper aims to present a reasonably accurate, simple and practical method of considering the main economic factors which govern design.

Jan 1, 1962

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 Andrew R. L

The Kintyre uranium deposit was discovered in 1985 in the course of following up radio- metric anomalies generated in an earlier air- borne survey. The latter survey was conducted primarily to acquire aeromagnetic data for diamond exploration and the uranium discovery was made during a subsequent campaign of base- metal exploration. CRAE commitment to the Rudall area for a range of commodities over a period of 13 years made a significant contrib- ution to the discovery of Kintyre. Other con- tributing factors included CRAE's multicommod- ity approach to exploration, management support and continuity in the geological team. The Kintyre uranium deposit (Fig. 1) is located on the northern margin of the Rudall Metamorphic Complex, 60 kilometres south of Telfer and 260 kilometres north northeast of Newman, in the Paterson Province of northern Western Australia. It is 700 metres inside the northern boundary of the Rudall River National Park (15695 sq. km) and lies between the Great Sandy Desert and the Little Sandy Desert (Beard, 1969). Intense weathering since the Permian has produced a subdued landscape around the deposit. Resistant rock types still retain an older plateau surface but it is incised by more recent streams. Other Proterozoic and Permian rocks form low, sometimes rocky, areas largely covered by aeolian sand.

Jan 1, 1988

Rehabilitation has been very effective in the short to medium term in providing a cost effective and reliable means of containing the side effects of land disturbance. However, there is still insufficient data to critically evaluate the sucess of rehabilitation in the long term. There is an urgent need to develop objective criteria to monitor the sucess of rehabilitation. The aim of rehabilitation in Australia has traditionally been to return disturbed land to natural vegetation compatible with the surrounding area. This objective has often been accepted instinctively without adequately addressing alternatives.

Jan 1, 1992

In those days no one worried - there were plenty of other things to do. But in'these days it is different. Everyone worries- and. because there is so much worry, emotion has entered the picture. And, worse than that, capital is being made in political circles. People who were quite unaware, five years ago, that any problem existed, have now become experts on the subject, and shout to high heaven that something should be done - and yet they go on using the leaded high octane petrol they deplore so much. And even scientists, who should know better, adduce only such evidence as fits the argument in hand. And the Press is not without blame - some of its reportings is open to serious question, whatever may be the excellence of its motives. The point is made that one should know what one is talking about. And make sure that the evidence quoted is fact - and make sure too, that all the evidence is used, not only that which suita the argument.

Jan 1, 1971

By Hall K

The Osborne copper gold mine, 100 per cent owned by Placer Pacific Limited, is situated 195 kilometres south east of Mount Isa. The orebody is broadly categorised into three main ore zones; oxide, transitional and sulphide copper. Copper oxide

Jan 1, 1997

By Van Rooyen F

An introductory review of the current grade control blasting techniques (selective mining strategies) used in the Eastern Goldfields has recently been undertaken. The survey was initiated and conducted by the Western Australian School of Mines. Four distinct selective mining strategies have been identified and a number of trends have been highlighted. Many operations, however, have developed techniques which use a hybrid method to suit the site conditions. The aim of all the mining strategies is to produce an optimum product. The optimum product is one which contains no diluent and experiences no mixing of the various identified ore and waste blocks and is fully reco- vered at the minimum overall operating cost. Due to this unified aim all of the grade control blasting techniques have many common design Features.

Jan 1, 1988

By Minglin W, Zhixing L

The laws of detonation wave velocity variation in propagation process along the charge under channel influence are investigated widely in this paper. The result is obtained by blasting experiments. Bore hole is simulated by plastic tube or steel pipe (with outer diameter 45 nun, inner diameter 40 or 41 mm). Blasting experiment is carried out with a cylindrical charge of 32 mm diameter. The author analyses the characteristics of energy distribution along the charge under above-mentioned conditions. Reasonable initiating position and initiating direction are also analysed. A double-direction initiating method which consists of several initiating charges is put forward. The blasting effect of this initiating method when used in underground mining is stated out.

Jan 1, 1990

I propose to speak today about our mineral heritage. In common usage "heritage" refers to the past. It means the discoveries, the developments, the mines and the processing plants, the benefits, the consequences, and the human experiences flowing from these. The history of the industry, inseparable from the history of the countries in which The Institute operates, is a rich background of which we can all be proud.But there is also a much wider meaning to mineral heritage. Our past has left us with the ab\lity to create and operate world scale enterprises generating wealth for the community, the ability to offer satisfying and challenging careers in a wide range of skills to our young people, and the willingness to follow adventurous and challenging vocations in remote areas, away from the big cities, at a time when the mentality of many is to get the most for the least effort and at the least inconvenience to themselves. The industry continues to be the repository of the pioneer spirit and a vital contributor to improving the life of the people in our countries.Thus, while our mineral heritage has much to do with the past, an essential part of it is how we use this rich past to build and shape our future. It is in this broader context that I am speaking today.

Jan 1, 1990

Mineral resource estimation is commonly based on the accumulation of a series of local estimates. At times, the distribution of these grade estimates is not appropriate to the grade distribution of the data on which the estimates are based. Mineral resource grade estimation has an increased potential of being in error as the grade variability increases. As the mineral commodity value increases, greater grade variability within the mineral resource is tolerated. This paper directs its attention to mineral properties where the data average grade is 20 per cent or more than the data median grade at a specific cut-off grade. A mineral resource estimate is enhanced if it is supported by graphs which demonstrate that the sample data have been separated into appropriate geological domains. Each geological domain has a unique grade distribution signature, which can be graphically demonstrated simply and objectively. This signature will usually be evident well before the Indicated mineral resource estimates are available. The paper looks at the use of the log probability and MedAve plots to assess how effective domaining has been. It further outlines how the MedAve plot can be used to assess the integrity of the mineral resource grade estimate within a geological domain with the data on which it is based. The paper suggests that the overall grade of a mineral resource at any cut-off grade will be closer to the data median grade rather than the data average grade. Tips are provided to ensure that the odds reflected in the data grade distribution are not ignored and hence the risk that the project is affected by unrealistic estimates of the overall mineral resource grade is reduced.

Jan 1, 2003

By Binns RA, Murao S

The PACMANUS and Jade deposits are two active hydrothermal fields that are forming massive sulfide deposits at the Pacific rim margin. Both are associated with felsic submarine volcanic rocks and both occur in back-arc settings. However, PACMANUS is associated with almost sediment-free dacites and lies on the crest of a volcanic ridge, whereas Jade occurs in a heavily-sedimented tectonic depression associated with a basement of pumiceous rhyolite. The PACMANUS deposit is richer in Cu and Au, and Jade in Pb. Zinc, Ag, As and Sb contents are similar. Sulfide textures at PACMANUS suggest formation of Cu and Zn sulfides by simultaneous double-diffusion involving inwards-moving seawater mixing with outwards-moving hydrothermal fluid. By contrast, at Jade there is a more complex history of formation where initial growth of barite on the sediment surface, probably associated with microbial activity, formed an impervious cap which trapped higher temperature hydrothermal solutions.

Jan 1, 1995

THERE is available a considerable amount of literature concerning the practice, and, to a smaller extent, the theory of ventilation as it applies to coal mines. Publications considering the subject of ventilation of metal mines from a practical viewpoint are much less numerous, whilst the treatment of the theoretical aspect of the question (except in so far as is common to coal mining) appears to have been almost neglected. This may be due to one of two causes (a) That in many metal mines (especially those which have not attained a great depth), on account of the greater number of connections with the surface, as compared with coal mines, natural ventilation has sufficed.(b) That in metal mines where the foregoing is not the case the solution of the ventilation problem from theoretical considerations has been regarded as involving so many complications that any attempt at the determination of a set of concrete ventilation figures applying to and throughout the mine would be futile. Whilst it is freely admitted that the difficulties inherent in the application of theory to the ventilation of metal mines are numerous, it must also be admitted that few attempts have been made to overcome them. The ultimate aim, of course, would be the collection of sufficient data to enable the probable behaviour of the air-currents throughout the whole of the workings of any mine to be accurately predicted under any particular set of circumstances. Failing the attainment of this goal of perfection, it would at least appear that much valuable information might be obtained. In ventilation, as in...

Jan 1, 1921

The care necessary to ensure a reliable estimate of average value from the individual values of a series of bore holes sunk in any alluvial deposit containing coarse gold was well exemplified in checking over the mining returns from a previously bored deposit in Central Otago, N.Z. While the working returns are always liable to vary considerably from bore values in any particular sub-section of an area, still, over any considerable area, the two must check within small limits, if profits are to be calculated and capital raised on the average value given by boring.The present figures have probably more value than those from, dredge returns since accurate measurements are difficult to obtain in irregular water-filled dredge paddocks, whereas in the case under review the paddock walls stood almost perpendicular, and, as the measurements were taken and checked in the empty rectangular excavation, the yardage estimate may be taken as substantially exact.NATURE OF DEPOSITThe area consists of a narrow valley deposit of fluvio-glacial origin, the original deposit having been eroded and the gold reconcentrated by post glacial rivers. The wash is between 80 and 90 ft. deep, and is formed in two distinct layers:(i.) The top layer from surface to 70 ft. or 80 ft. consists of about equal quantities of gravel mixed with glacial drift, and a small amount of clay. The gravel is typical discoid glacial stone of a maximum size of about 4 in. diam. by 1 in. thick, and consists of soft micaceous schist and laminated slate. This upper layer of wash contains no coarse gold whatever, and very little fine; indeed, in mining, the top 30 ft. is discarded without being passed over the boxes.(ii.) The lower layer of wash to bedrock is similar to the upper, except iihat it contains about 10% of larger discoid stone up to 12 in. diam. by It in. thick; 90% of the gold is concentrated in this bottom layer.

Jan 1, 1929

The Illawarra Branch of the Australasian Institute of Mining and Metallurgy over recent years has established an enviable reputation for organising and conducting conferences, colloquia and symposia. And this Symposium must surely enhance that reputation. The subject of the Symposium, Seam Gas Drainage has become a matter of great import- ance to the Australian Coal Industry in a comparatively short time. Our short experience being due to our operations, until recent times anyway, not being unduly affected by gas. The Australian Industry, by virtue of its mines getting deeper and higher rates of extraction being required is now encountering the difficulties with gas which have for so long been part of the coal mining scene in many other countries. Because these gas emissions affect our working conditions by way of creating hazards and affect our production by way of bringing about cessation of operations from time to time this Symposium must be regarded as being very timely out here. I must congratulate the Branch Committee on the general set,yp :o.f the programme of papers. The classification of papers into four groups and the sequence in which the papers were presented provided an excellent flow through from introduction to finality. It is not my intention to further discuss individual papers - already they have been well discussed in this forum and as I understand it outside in the early hours of the morning,

Jan 1, 1982

By P Church

What is the best method of splitting a sample from a reverse circulation drill rig? How important is it to obtain a correctly split sample? What is the impact of an incorrectly split sample? These are just a few of many questions asked daily in the mining industry with regard to sampling. Modern sampling theory is well described in the literature in texts and is taught in short courses throughout the world, however little has been published on the relative performance of sample splitting devices used in the field. This paper compares the performance of the Jones tiered riffle splitter with a cone splitter manufactured by SGS Metal Craft in Western Australia. The testwork was carried out at AnglogoldÆs Sunrise Dam Gold Mine, 55 km south of Laverton in Western Australia. Mineralisation at Sunrise Dam is hosted in a structurally complex framework of shear zones with dips that range from steep (70¦) to shallow (25¦). The deposit is characterised by significant amounts of coarse gold, which presents a challenge in sampling, analysis and grade estimation. The three major areas where sampling errors can occur are in drilling, sampling, sample preparation and analysis. Sampling errors attributable to drilling and sample preparation often far outweigh the errors made at other stages in the process, however historically most effort to identify sampling errors has concentrated on the laboratory and analytical procedures. Splitter design and cleanliness can have a large impact on sample collection and preparation. Splitter performance was tested with respect to sample weights, particle size distribution, and gold grade consistency. The aim was to determine if each particle has an equal probability of being sampled, the resulting sample has integrity, and if any segregation problems occurred. The cone splitter was found to provide the best split in terms of particle size distribution, with no apparent size bias. Duplicate samples had more comparable masses than those provided by the riffle splitter. Most importantly, the cone splitter gave less grade variability between duplicate samples than the riffle splitter. Testwork also confirmed that, like the riffle splitter, the cone splitter must be oriented vertically and the design of the rig or cone splitter trailer should accommodate this requirement.

Jan 1, 2003

This paper describes preliminary research on the application of Markov Decision Processes (MDP) to Real Option Valuation (ROV) and the optimisation of mine scheduling. The MDP framework is a novel approach to option valuation and scheduling in mining operations. A learning agent is introduced into the valuation process of an open pit, where prices and block ore grades have probabilistic values. The prices are modelled using a mean reverting diffusion process and the block grades using sequential Gaussian simulation. The agent is asked to learn which production parameters should be used in order to maximise the overall value of the project. The introduction of the agent permits a real option approach to mine valuation, such that the value associated with the robustness of a design to uncertainty can be measured. A simulated example is used in which there are ten blocks to be extracted under conditions of grade and price uncertainty. Using policy iteration, an optimal policy is generated and the value of production options is found. The potential financial gains from applying MDPs to mine valuation and optimisation are substantial and warrant further investigation.

Jan 1, 2007

Microorganisms have been used throughout history for the benefit of mankind with some of the earliest applications being in the production of fermented foods and beverages. Reactions involving inorganic substances such as metals, sulphur and sulphide compounds were hardly ever used until the early 1900s when it was discovered that Thiobacillus ferrooxidans was capable of promoting the oxidation of metal sulphides in ores. Today, it is widely recognised that biotechnology has great potential in the minerals industries, particularly in such areas as the leaching of low-grade ores of metals such as copper, gold and uranium; removal of heavy metal ions from process streams and from liquid process wastes; and in the desulphurisation of high-sulphur fuels. Although widespread commercialisation of mineral biotechnology has not yet been achieved, it is estimated that by the Year 2000 mineral biotechnology will have a significant impact on the minerals and metal industry and will probably account for tens of billions of dollars worth of annual production world-wide. This paper examines the actual and possible future applications of biotechnology in the minerals, metal refining and fossil-fuel processing industries. Firstly, the important chemical (and biochemical) principles involved in bio-dissolution of metals from ores and solid wastes, and in bio-accumulation of metals from process and waste solutions are reviewed, including leaching practices - past, present and future. Microbial desulphurisation of coal, and microbially-enhanced oil recovery are also discussed. The practical aspects of genetics and genetic engineering, the types and characteristics of those microorganisms important to mineral biotechnology, and the current research trends are reviewed as well. KEYWORDS: Biotechnology, microbial leaching, bioaccumulation, biosorption, bioleaching, biohydrometallurgy.

Jan 1, 1993

The patterns of flow of reaction gases through the flash furnace at the Kalgoorlie Nickel Smelter were simulated in a 1:20 scale model using a flow of water. Particular features of the flow down the reaction shaft, through the settling chamber and into the uptake leading to the waste-heat boiler were examined. Inferences were made concerning the effects of the patterns of flow on the efficiency of the smelting reaction, on the entrainment of dust by the gas stream and on the erosion of the refractory lining of the furnace. In addition, the effects of geometrical modifications to the arrangement of the concentrate burners and to the profile of the settling chamber were explored by making these changes to the model and observing the resulting variations in the patterns of flow.

Jan 1, 1991

The Paracale gold region had been known for hundreds of years, but the first professional attempts to work the lode and alluvial deposits were made only in the 1890s by the London-based Philippines Mineral Syndicate. Complex ores, transportation problems, and the Philippine Insurrection halted operations. Ultimate success went to American firms, though Frank Karuth's Philippines Mineral Syndicate had pioneered the field.

Jan 1, 1987

By M Rispin, R Karlson

Chemical admixtures are not commonly included in the variety of backfill mixes used in the mining industry. This may be attributed to several reasons including, but not limited to: the perceived high added cost, the lack of awareness about their proper use, and the lack of knowledge about their features and benefits. In the construction industry today, however, chemical admixtures are used in the majority of the concrete produced, enabling concrete to become a more cost-effective building material. They also enable construction crews to meet demands for year-round construction, quicker completion of construction projects, and improved concrete properties. The high demand for chemical admixtures in the construction industry has led to numerous innovations in admixture technology in recent years. Some of these chemical admixtures have been found to enhance the production, transport, placement, and in situ properties of backfill mixes. Others have been found to reduce the cost of such mixes while maintaining, and in some cases improving, their physical properties. In this paper, a few of such innovative admixture technologies are discussed. The benefits, imparted by these technologies to backfill mixes as well as performance data on their use in several backfill applications at various mines, are presented.

Jan 1, 1998