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Ranger Uranium Mines Pty. Ltd. operates an open pit mine and ore treatment plant in the Northern Territory designed to produce 3 000 tonne/yr of U308 in yellowcake from 3 500 tonne/day of mill feed. The construction of this project was completed in 1981, 12 years after the discovery of the orebody. Wright-Davy, a Joint Venture of Wright Engineers and Davy McKee Pacific, were the Project Managers and Designers of the $270 million ore treatment plant and associated infrastructure. The project was designed in Sydney in -an office integrated with the Client, staffed by 35 key personnel drawn from Wright Engineers and Davy McKee, supplemented by personnel hired for the project. The peak Wright-Davy workforce in Sydney of 200 contained 113 design staff. The design principle of using the best practicable proven technology resulted in a plant which easily produces its design output using ore types outside the design criteria. The structuring of the project systems and industrial relations policies contributed to construction being completed within time and under budget. The plant was built without any major industrial dispute occurring and no dispute arose due to the uranium issue.

Jan 1, 1983

By M E. Malmstr÷m

Quantification of site-specific sulfide oxidation rates is crucial to accuracy of prediction of, for example, the environmental impact of a mine site. Sulfide oxidation reactions are reportedly increased by bacterial mediation; determination of abiotic and biotic weathering rates thus requires the establishment of sterile control samples. However, sterilisation often involves exposure of samples to extreme conditions that may alter the physical, chemical, or mineralogical characteristics of the tailings and hence affect element release rates. The impact of various sterilisation techniques, common and novel, on the element release rates from tailings from the Kristineberg site, northern Sweden, has been investigated. Batch weathering experiments indicated that the different methods of sterilisation (autoclaving, heat treatment, ethanol/heat treatment, application of antibiotics, rinsing with distilled water, and γ-radiation) did not greatly affect long-term element release rates. Long-term experiments (>30 days) are thus to be recommended for establishment of weathering rates. Sterilised and untreated control samples showed similar element release rates after ~100 days of experiments; possible explanations include that microbial oxidation is not important under our experimental conditions (Po2 = 0.2 atm, pH ~2.3, 22¦C, 0.01 M HNO3, no additional nutrients).

Jan 1, 2003

The word "optimization", refers to the search of an economic optimum, or, more precisely, to the choice of technical parameters which will define the more profitable mining project, knowing the values of the economic parameters. In fact, there is no direct way to perform this optimization, because the extremely large number of technical factors involved, from the type of working and its selectivity to the characteristics of the mill and its flexibility, makes it impossible to make a comprehensive survey of all possible projects. Beside, it would be meaningless to engage in such a task as the deposits themselves are not really known, but only estimated, with sometimes a high level of imprecision. Not to mention the numerical instability which would affect such a computation! In addition, the "best" project is not necessarily the one which strictly maximizes a given profit formula. There also exist human factors which have to be complied with, when choosing the cutoff grades for instance. Finally, there are other non-numerical factors which interfere with the choice between several projects: the shape of the bottom of a pit of the layout of the access road for instance.

Jan 1, 1986

After reviewing the many excellent papers being delivered here, it is apparent that we are all concerned with the same general subjects of commodity agreements, international cartels, and anti-trust problems as well as the impact of governments on resource management and minerals pricing. Accordingly, as a relative newcomer to the mining business, I feel that my most meaningful contribution can be made by taking a more philosophical look at the future of our system of democratic capitalism. Unfortunately, governments the world over seem intent on jeopardizing the high standards of living resulting from the Industrial Revolution and furthered by the emergence of its by-product, capitalism. This tendency is particularly germane to the basic natural resource field, since government regulations, controls, and intervention in mining far exceed even the constraints normally imposed on hard-pressed consumer-oriented businesses. Increasingly, many governments seem to feel that natural resources no longer belong to private individuals but rather are the property of the state to be developed in a regulated manner and usually in a way directly contrary to the functioning of the free market system.

Jan 1, 1978

The advent and easy availability of fast and powerful digital computers has marked a transition from one era to another in the field of process control in many industries. Mineral processing is no exception. Aims, practices and problems associated with process control of mineral beneficiation plants in the 'old days' are compared with those available at present. Although basic processes remain generally the same, there have been simultaneous social and economic developments, which directly relate to the development and present value of process control. Lower head grades are now treated, plant capacities have increased, and a large proportion of future capital in the mineral industry will be associated with large capacity plant, treating still lower grades. Environmental considerations have pressurised moves to better control in some areas. With these changes, economic operating incentives have changed, and process control has, in many plants, become more critical. Finally, while computer technology has developed recently at a very rapid rate, developments in the fields of instrumentation, basic on-line measurement and sampling have in general lagged behind, limiting the progress possible in process control. Hence, the benefits of computer control vary depending on

Jan 1, 1977

Access roads for haulage, construction or maintenance purposes are discussed with particular attention being given to the un- sealed "all weather" form of construction for Off-Highway applications. The service conditions experienced by the surfaces used in these roads is examined. These conditions are discussed in terms of the conventional engineering properties used for natural gravel material selection. Experience gained during the construction of a pipeline access track is used to illustratE material selection guidelines based on geological input and an understanding of good construction practices. TMITDnIll IrTT Ohl In many Australian situations off-highway haulage by wheel or track supported vehicles is carried on unsealed, gravel roads. Although the unsealed gravel road is the back-bone of the rural road network in Australia, in general, traffic loadings are relatively low compared to the off-highway unsealed haulage road. The cost of the haulage/access road construction component is one important factor in project planning which needs careful consideration. It is no longer acceptable that the initial rough exploration track be gradually upgraded so that it will eventually carry construction and maintenance traffic safely and efficiently. Fatal accidents and

Jan 1, 1982

Mining, like most other businesses, is based upon capital assets; and the primary cap- ital of any mining company is its ore reserve. A company's survival and growth is, thus, dep- endent upon its ability to replace, increase, redistribute and to diversify its ore reserves. A Kennecott executive addressing a group of geologists in 1957 stated, "Management expects a geologist to find ore! That is the primary objective and the justification of the geologist in the minerals industry. There is no other function that we can rationalize." This is, however, a restricted point of view, and one which I an sure is not fully shared by mining executives or mine operators at the present time. Ore reserves are 'made' as well as 'found' and the geologist contributes to this process. A mining geologist engages in activity in- volving the study of geology in connection with the total mining operation. His major task is the adaption of geological knowledge of ore de- posits and rock behaviour to mining needs, and the application of principles of the science of geology to specific problems of finding, develop- ing and extracting of ore bodies.

Jan 1, 1975

By J Czerwinski, M Kasper, M Wyser, N Heeb

The VERT project 1993 - 1998 laid the technical foundation for curtailing the emission of fine particles from diesel engines at Swiss underground workplaces. The targeted maximum was 100 ¦g/m3 EC. Extensive laboratory and field investigations demonstrated that this specification is only attainable with modern diesel particulate filter (DPF) systems that almost eliminate particles in the entire lung penetrating size range from 20 nm to 2.5 ¦m. In January 2000, Switzerland mandated compulsory particle filters in underground workplaces, particularly in tunnelling, irrespective of engine age, size and type. After the implementation, the particle concentration in the respiratory air was below 40 ¦g/m3 EC, compared to earlier values of up to 750 ¦g/m3 EC. Deployed DPFs have proven filtration rates of 99 per cent in the entire size range of alveoli intruding particles. The DPFs are as durable as the engine, suffer no ageing and require minimal maintenance. The failure rate is below three per cent annually. Of the 6000 retrofitted construction machines in Switzerland, about 400 are deployed underground. Prerequisites for this quality are a sophisticated certification procedure, electronic monitoring of DPF operation and meticulous periodic exhaust gas inspection of the engines.

Jan 1, 2005

Mining, like most other businesses, is based upon capital assets; and the primary cap- ital of any mining company is its ore reserve. A company's survival and growth is, thus, dep- endent upon its ability to replace, increase, redistribute and to diversify its ore reserves. A Kennecott executive addressing a group of geologists in 1957 stated, "Management expects a geologist to find ore! That is the primary objective and the justification of the geologist in the minerals industry. There is no other function that we can rationalize." This is, however, a restricted point of view, and one which I an sure is not fully shared by mining executives or mine operators at the present time. Ore reserves are 'made' as well as 'found' and the geologist contributes to this process. A mining geologist engages in activity in- volving the study of geology in connection with the total mining operation. His major task is the adaption of geological knowledge of ore de- posits and rock behaviour to mining needs, and the application of principles of the science of geology to specific problems of finding, develop- ing and extracting of ore bodies.

Jan 1, 1975

Hamersley Iron Pty. Limited has maintained an interest in the screening of iron ore fines (nominally -6 mm). However, no dry screening process had successfully demonstrated acceptable separating efficiencies at high tonnage rates, low operating costs, and mechanical reliability when screening iron ore fines (containing up to 6% free moisture) at sizes of around 1 to 2 mm. A new type of vibrating inclined screen has recently been developed which is claimed to have a non-blinding screening surface. It was decided to test a pilot scale unit in an existing pilot plant located at Hamersley's facilities at Dampier, Western Australia. The appropriate operating parameters such as vibration speed and feed rate were determined using one fine ore type. Mats with different aperture sizes, and different feed moisture contents were also tested. Trials were then conducted on various fine ore types to indicate the effect of different size distributions on separating efficiencies. The effects of feed moisture content were determined with these ore types, and a blend of lump (nominally -30+6 mm) and fines was tested to compare the screen's performance with that of the bottom deck of the minesite product Screens.

Jan 1, 1991

By McKew M, OÆRegan

Rapid access longwall mining' or 'longwail punch mining' is a proposed extraction method whereby longwall gate roads are driven into a seam directly from an opencut highwall. The longwall panel thus formed is retreated back to within 40 m of the highwall providing an extremely simple, reliable and therefore highly productive longwall mining system. The concept is of particular benefit for the recovery of isolated pockets of coal (adjacent to a highwall) not easily accessible from a conventional underground mine. As panel gate roads are driven directly from the open strip, minimal delays are incurred between the end of open cut and start of underground production, allowing the method to bridge the gap between open cut mining and a total underground commitment. The study was specific to the Bowen Basin, and given the likely conditions, no significant operational or geotechnical hinderances to the concept could be identified. It was therefore concluded that longwall punch mining would not expose the operator to any additional risks above that normally associated with the introduction of longwall mining. Thus, longwall punch mining is an attractive option, both operationally and financially, for open cut mines reaching their maximum economic Death.

Jan 1, 1988

A study is presented of the theoretically possible initiation systems for outbursts and the subsequent propagation mechanism.Previous occurrences of outbursts and their correlation to the theoretical system are described. An estimation of the energy release from two energy sources, gas strain energy and rock/coal strain energy, is presented and the relative importance of each source in the severity of outbursts. Summary: The description of mechanisms of outbursting follows the examination of these phenomena at Collinsville in Bowen No. 2 mine and at Leichhardt Colliery, Blackwater. Quantitative material contained in the paper refers to Leichhardt Colliery, Blackwater. Clearly from the work carried out to date gas release has a major part to play in the out- bursting at both of these collieries. In the case of the December 1 1978 outburst at Leichhardt Colliery energy release estimates place gas strain energy release contributing eight times the energy of that from rock/coal strain energy. Even the normal outbursts at Leichhardt Colliery appear to show this trend. Estimates of energy released are for comparative purposes between gas and rock strain energy and the values obtained may be regarded as approximate.

Jan 1, 1980

Since 1958 there have been 16 major coal mine explosions in the U.S. claiming 323 lives. Whilst the exact cause of a number of these incidents has not been determined, the majority has involved gas ignitions in one way or another. In addition there have been fatal gas explosions in salt mines and vapor explosions in oil mines. Furthermore, many of the oil shale mines in the U.S. have proven to be gassy giving cause for concern. Compounding these problems is the fact that frictional ignition of methane in coal mines has dramatically increased over the past several years; over 100 such ignitions were reported in 1979. While, no fatalities have been attributed to frictional ignition in the U.S. since early 1978, a recent mine explosion in Nova Scotia which resulted in 11 fatalities was attributed to a frictional face ignition. Research being conducted at the Bureau of Mines is aimed at the prevention and suppression of gas explosions. Emphasis is placed on new coal cutter bits for reducing ignition frequency, machine-mounted water sprays for preventing frictional face ignitions and automatic devices for quenching incipient ignitions and fully developed gas explosions.

Jan 1, 1981

The mineralogy, maero- and micro-textures of Thackaringa ore are simple and have many counterparts among base metal-quartz-siderite vein type deposits elsewhere.The ore consists predominantly of galena, sphalerlte, chalcopyrite, tetrahedrite, and arsenopyrite in a quartz and siderite gangue. Silver minerals, as such, appear to be lacking and silver values are no higher than in other sulphide ores of this type. These features contrast very markedly with those of the A.B.H. Consols Lode which appears to have emanated from the north end of the Broken Hill Main Lode Horizon during high grade regional metamorphism. The Consols Lode has been regarded as of Thackaringa type, and both are regarded as possibly arising from the remobilization of Main Lode Horizon ore. Whilst this may yet prove to be so it appears that the marked differences in mineral composition between the Consols and the Thackaringa types, would require somewhat different modes of regeneration.Thackaringa ore, as well as A.B.H. Consols ore, on this basis, would necessitate the development of a metahydrothermal ore fluid to account for their present apparently hydrothermal (or pseudo-hydrothermal) constitution...

Jan 1, 1967

By Boontanjai C, Boyapati ER

Reagents used for batch flotation tests were Aeroxanthate-343 & 350, Dow Z-6, & reagent-4037 (from Benambra) as copper collectors; Na2SiO3 & Na2S2O3as gangue depressants; lime & HCl as pH regulators; and pine oil & MIBC (methyl isobutyl carbinol) as flotation frothers. A Denver Sub A flotation cell of capacity 250 gms was used for the batch flotation experiments. Atomic absorption spectrophotometer was used for copper assays and microscopy for selectivity and liberation studies. Melbourne tap water was used throughout the experiments. Unless otherwise stated, the following parameters apply to the flotation experiments: flotation impeller speed - 1300 rpm, pulp density during flotation- 22%, reagents addition - in 4 stages, total conditioning time for collectors - 8 minutes, total flotation time- 9 minutes. A variable quantity of copper mineral collector according to the test in question was added, then conditioned the pulp for 2 minutes. The froth was removed by hand, scraping the full length of the cell at constant depth every 10 seconds. No frother is required for this copper tailing flotation. Four concentrates were collected after addition of collector and conditioning at 2,4,6 and 9 minutes. The pulp volume was maintained at a constant level to yield a constant froth depth.

Jan 1, 1990

Giving the keynote address in the final session of a conference dealing with closely related topics has a disadvantage in that much of what can be said has been said. It also has an advantage, however, because it presents the speaker with the opportunity to integrate and analyse the material presented by the various speakers. I would like to look to the near future in Aust- ralia and the United States of America, to the risks, problem areas, and changes of a rapidly evolving post-industrial era-an era we are begin- ning to experience where industry no longer `calls the tune'. We miners have been quick to point out and emphasize, that ours is a `high-risk' industry in the world of business and commerce. Yet, clearly those who have survived, and been successful, have learned to anticipate and cope with risk and change. This ability has been a distinguishing feature of the industry's leaders who, in market studies and commodity selection, exploration and development, mine planning, metallurgical pro- cessing, and general administration and operation 1. identify areas of risk or inevitable change, 2. analyse, test and quantify those factors of risk or change, and 3. design methods, systems, equipment to elim- inate, moderate, or control or economically compensate for predicted risks or changes.

Jan 1, 1978

This brief introduction tries to introduce delegates to this conference to the almost unbelievable attributes possessed by many microbes which might be relevant to geomicrobiology, and how most of these remain unexploited by us. It introduces some of the terminology which will be used and tries to suggest that there are rewarding times for those who set out to discover the natural biodiversity of bacteria in nature. Although we have exploited microbes, usually unwittingly, and suffered at their hands for millennia, it is only recently that we have begun to become aware of how they dominate our planet (most of the earthÆs biomass is bacterial) and are responsible consequently for most of what happens here. A few can cause us harm and occasionally kill us, but most bacteria are beneficial, impacting positively for example on how we grow our food and in cleaning up the pollution we create. They are simply indispensable to how we live. They have been responsible for many of the geochemical changes which have taken place on this planet and play major roles in the transformation of elements so essential to our existence (Newman and Banfield, 2002). No one should dismiss them as minor players in our game of life.

Jan 1, 2004

In order to formulate appropriate and useful education and training policies and practices, it is crucial to firstly consider the demographic environment of our workforce-and the direction in which it is (known to be) heading. We can predict with a degree of certainty, that the role and influence of training on the future survivability of organisations will- become increasingly critical. This will be particularly relevant for those industries and organisations which are technologically based. The ad-hoc use of training is and, will no longer be appropriate. Organisations must move toward the on-going use of a dynamic education and training strategy based on an effective staff development programme, which meets the short and medium term needs of the organisation. The Technisearch approach is based on maximizing the efficacy of training and learning. The package provides.a total service to meet clients training needs using educational techniques geared to adult learning. it stresses the importance of ongoing research into industrial adult training and its effectiveness in improving skills and productivity. Current research on roles of supervisors in the Australian workplace and the development of the Supervisory Behaviour Questionnaire. (SBQ) indicates the need for a proper framework within which the objectives of training can be addressed.

Jan 1, 1986

By Salehi M. R

Although inherent mineral matter appears to have no effect of the reflectivity of inertinite in the reflecting light microscope, it has a marked effect on the grey levels resulting from the backscattered electron response in the scanning electron microscope. Inertinite with a high inherent mineral matter content has a high grey level response but not as high as that of mineral matter. The highest grey level response is with inertodetrinite which at times could be mistaken for mineral matter. Fusinite has a higher grey level response than semi-fusinite. The backscattered electron grey level response corresponds to average atomic number and hence approximately to density. If a porous structure develops and becomes filled with mineral matter such as S, Cl, Ca, Si, and Al the grey level will be higher. Micrinite has an unusual response in that it behaves like an exinite maceral in the SEM rather than an inertinite maceral. It either has a low grey level when relatively free of inherent mineral matter, or a low grey level background with high level granules corresponding to Si and Al dominantly. Similar structures have been found in exsudatinite and resinite. It is thought that micrinite results from the migration of hydrocarbons out of exinite giving a porous structure which usually accommodates inorganic matter.

Jan 1, 1991

The geochemistry of waste rock from mining operations is critical to the development of acidity-related environmental problems during mining operations, and following mine closure. Failure to recognise the potential for waste rock to produce acidic oxidation products may cause mobilisation of heavy metals into ground and surface waters, and create heavy metal levels in soils which are toxic to plants, causing the failure of revegetation programs. Although more usually associated with wet tropical environments, the potential exists for these problems to occur even in and regions such as the Eastern Goldfields region of Western Australia unless appropriate pre-planning is undertaken.Acidity-related mine waste problems can be extremely expensive to rectify, but can be avoided by waste rock characterisation, and pre-planning of waste rock deposition based on this information. Integration of knowledge of waste rock geochemistry with geotechnical engineering, and application to likely problems, is essential for the successful planning and implementation of cost-effective strategies to avoid problems occurring. Pre-planning to avoid problems is likely to be significantly less expensive in most cases than remedial actions to rectify problems after they have occurred, and in fact may involve no additional cost if it requires only rescheduling or redesign of existing or planned Activities.

Jan 1, 1993