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By Hall ST, Miles NJ

Recently an inorganic salt, sodium polytungstate (SPT), has become available that allows the preparation of non-toxic solutions of relative densities up to 3.1. It is relatively expensive and at the higher relative densities achievable, highly viscous. Alternative inorganic compounds may in the future be identified that overcome these limitations. The Australian Mineral Industries Research Association Ltd (AMIRA) has initiated a project to examine possible alternatives. However, it has been found that by the addition of finely divided ferrosilicon to solutions of SPT, relative densities of up to 4.0 can be achieved. A laboratory technique for density fractionation of sized mineral samples utilising this finding has been developed. This is currently being extended to study the potential applications of such liquids and suspensions in dynamic systems for mineral, coal and recycled waste separations.

Jan 1, 1993

This paper addresses the unique environ- mental programmes which prevail at Ranger and their importance in the future profitability, of Ranger Uranium Mines Pty Ltd. (RUM) Industrial relations, general safety, and occupational health have long been regarded as part and parcel of the concept to 'manage for profits'. More recently, the need for environmental protection has also become an important management consideration. This is particularly so at the Ranger Uranium Mine where environmental protection is very closely and continuously regulated. Since the commencement of operations at Ranger some three years ago the company has operated within these regulations and demonstrated clearly that yellowcake can be produced efficiently, economically and safely. The company also recognises that in order to ensure continuity of production, it will have to continue to operate within these strictly supervised Regulations.

Jan 1, 1984

By Summers DA

Faculty at the University of Missouri-Rolla have carried out research on the application of high pressure water jets as a means of excavat- ing coal for over 15 years. During the course of this time, a number of different concepts have been explored--the most recent of which has been to use high pressure water jets as a means of extinguishing an underground coal seam fire. This paper will examine the use of some of these technologies and will consider the results as a basis for discussion of further applications of water jets in the future. The structural pro- perties of coal which distinguish it from other adjacent geotechnical material and provide a considerable advantage to water jet cutting, will also be presented and the advantages of using this tool will be discussed.

Jan 1, 1986

By Watkins JR

The educational system is a dynamic; a flow resource that can be significantly shaped, changed and - refined by educationists. This paper analyses these various facets of geo- science education in Australia. The Australian educational philosophy is essentially a laissez- faire model, a free market approach without any real government or professional directive or stratagem. Students are therefore free to choose their own educational pathway dependent only upon their ability and the access to courses. Geological education at the tertiary level in Australia is described and critically analysed. There is a real need for a rationalisation of geological education in Australia, and this rationalisation should include not only the number of courses offered but should also aim to fully define both the philosophy and purpose of geological education and the accreditation procedures for the Students.

Jan 1, 1986

By Madgwick J. C

Bacterial leaching of museum grade chalcopyrite and chalcopyrite concentrates at low sorptive relative humidities (55-91 per cent rH) was demonstrated. Optimum release rates were 13 and 27 mg/gram/100 days copper (Cu++) at 91 per cent and 80 per cent rH and 12 and 33 mg/gram/100 days iron (Fe++) at 80 per cent and 73 per cent rH for concentrate and "pure" chalcopyrite respectively. The optimum copper release rates occurred between 73 per cent - 86 per cent rH and 30-40 mM acid concentrations. Bacterial copper leaching rates were some twenty times slower for emersed copper concentrates, at low relative humidity, compared with submerged cultures. Bacterial copper solubilization was almost quantitatively inhibited above 150 mM acid levels (< pHO.8).

Jan 1, 1984

The treatment of beach sands in'' the Bunbury/Capel' area for the extraction of ilmenite is a very recent development in the mining industry in'J7estern Australia. Nevertheless since the commencement of production in 1956, ilmenite has become the sixth most important mineral produced. The increasing world recognition of W.A. as a major' Iiroducer of ilmenite is due primarily ' to its low chromic oxide. ; (Cr203 content,, 0,03% to 0.04%, combined with a medium to high grade TiO2 content, 54% - 6 , supported by large reserves, a'. stable government with close access to good shipping facilities.. Ilmenite is produced from-these deposits at low-costs, enabling the industry to compete on world markets despite high rates for sea freights because of the distance from.major markets.

Jan 1, 1964

By Pollard P. J

Australia is well endowed with both tin and tungsten resources, and is currently a significant producer of both commodities for the international market. The intensity of exploration activity for both metals has been rather sporadic, reflecting the changing market situation. Thus tin has experienced three major boom periods around 1880, 1907 and 1983, while tungsten prices peaked around 1917, 1953, 1970 and 1977. During the earlier periods, the major discoveries were located utilising simple prospecting techniques involving creek travers- ing and stream sediment panning. The resulting location of tin alluvials quickly led to the discovery of adjacent primary deposits. The major tungsten deposits were composed of quartz- wolframite, which was readily visible as mineralised float both within the drainage systems and on scree slopes. Thus by the early 1900s most of the currently significant deposits had been located. More recent exploration approaches have combined these tradi- tional methods with the development of exploration models based on evolving genetic concepts. Within tin systems the emergence of province styles of clas- sification combined with enhanced perceptions of tonnage-grade characteristics and improved geological models has enabled more effective exploration strategies. Province classification at the inter- national scale demonstrated a clear relationship between deposit type and geological environment and thus considerable attention was given to the range of provinces present within Australia. Tonnage-grade diagrams enabled the refinement of economic per- spectives, while detailed models provided the basis for localised search parameters.

Jan 1, 1988

The gold industry has been revolutionized in the last decade by market forces and technological changes. The latter are discussed in this paper, with particular emphasis on carbon-in-pulp (CIP) and heap leaching. The nature and scope of the process development aspects of a gold project are considered, and factors which determine process decisions are outlined, including the choice of CIP versus carbon-in-leach (CIL), agitated leaching versus heap leaching and treatment of ores containing copper and silver. Likely directions for development of gold processing in general are discussed, and metallurgical process options for treatment of ores of platinum group metals (PGM) are outlined.Metallurgical process development for gold and platinum group metals proceeds through a number of well defined stages, with input from various disciplines and information sources. The orientation phase will include preparation of a general project overview; careful consideration of the issue of sampling and sample preparation; characterisation of the resource in terms of ore types, mineralogy, chemical composition; development of appropriate methodology; and development of an understanding of the potential metallurgical unit operations.The process definition phase will be-'directed to development and definition of a notional process flowsheet, and will include identification and appraisal of process options; development of, notional process flowsheets; testing of flowsheets against ore types; ranking of flowsheets; initial engineering, including preliminary mass balances, equipment selection and plant layout; and broad-brush economic appraisal.

Jan 1, 1986

By P Dight

Increasing the strength of backfill has been the subject of much research. In the former Soviet Union most methods concentrated on the fill mixture including chemical additives, binder re-grinding, water electromagnetic activation and the use of vibration and turbulent activation. For the most part, this research has been confined to the laboratory where the results were not representative of field conditions. These methods also were directed at increasing the mass strength and were not specifically aimed at strengthening the fill where it may subsequently be exposed for instance on the side or underneath as it required for underhand cut and fill methods of mining. In the Republic of Armenia, a method of fill strengthening known as electro-activation has been adopted. The deposit it an epithermal gold deposit which to-date has been mined using underhand cut and fill with timber support. The backfill comprises cement and pumice placed in 2.5 m lifts. Central to the method of electro-activation is the placement of the electrodes in the stope in which the polarity and the electrical potential are changing during filling. The process promotes the binding of the fill layers, the bond to the side walls and to the adjacent fill. There is a significant increase in the compressive and tensile strength. The process has been used with beneficial effects on reinforced concrete and could be used in any mine utilising hardening fills.

Jan 1, 1998

Australia's gold mining industry has seen a resurgence in the past seven years - a resurgence the likes of which has been seen in very few, if any of this nation's other mineral industries. Industry experts are predicting that Australia could become one of the world's largest gold producers as the future of the South African gold industry looks increasingly tenuous under the present political crisis in that country. Therefore, it is utterly ludicrous for the Federal Government to introduce a tax which will see the Australian gold industry "wither on the vine."The Queensland State Government is utterly opposed to a tax on gold. Anyone in their right mind, who has seen the statistics could only agree with our stance. In 1984/85, activity in the gold mining industry is estimated to have accounted for over $750 million in national income, over$1,200 million in national output, and tax revenue of at least $115 million as well as providing more than 16,000 jobs. Chartered accountants Coopers and Lybrand's survey on the gold industry last year showed an increase in exploration expenditure by gold producers and explorers by up to 36% in 1986 from 1985 levels. That level is expected to be maintained in real terms for most of the remainder of the decade under the present tax arrangements. This is in contrast with the mining sector as a whole, where a recent Australian Mining Industry Council survey forecasted a 14% FALL in production.

Jan 1, 1986

Mining is a high risk industry where miners seek to secure certainty in all of their dealings. The introduction of native title to the Australian legal system with the High CourtÆs 1992 Mabo decision and subsequent Native Title Act 1993 has added to the risks associated with implementation and the ongoing operation of exploration and mining projects. The High CourtÆs Ward case in August 2002 confirmed Crown ownership of minerals and petroleum. But the Court also found that a mining lease that allowed an exclusive possession for mining purposes did not extinguish all native title rights and interests. Although the Court was specifically considering WA mining tenements, the WA mining lease is very similar to the mining leases and licences that exist across Australia, meaning that these tenements are unlikely to fully extinguish native title. The Ward case means that native title remains squarely on the table now and into the future for those involved in developing exploration and mining projects. However, certainty and workability is capable of being secured and this paper discusses some means by which this may be achieved. The paper starts by considering two of the many 1998 amendments to the æfuture actsÆ regime under the Native Title Act, Indigenous Land Use Agreements (ILUAs) and the application of ægood faithÆ negotiation to all negotiating parties. It then looks at native title agreements, other issues affecting negotiations and tips for negotiation technique.

Jan 1, 2003

Timely disclosure of information germane to the taking of investment decisions makes an essential contribution to ensuring the growth, efficiency and integrity of our capital markets. It is a core contributor to the maintenance of fair, orderly and transparent markets. Australia has a strategic need to protect and enhance market integrity. Australia is ranked tenth in the Morgan Stanley Capital International (MSCI) World Index, yet represents only 1.59 per cent of that Index. In order to survive and grow in this globally competitive environment, Australian capital markets û the drivers for economic activity in Australia û need to attract foreign investment and engage retail capital. The communication of relevant and comprehensible information to the investor plays a vital part in fostering investor confidence, thereby building depth and liquidity in our market. We have had a rewarding partnership with the mining industry to develop and recognise reporting standards which could allow ready comparability and investor understanding of the mining investment vehicle. Our mining market has been successful because of the high standards of professionalism and the intellectual capital that has been built up among the participants û the mining professionals, brokers, analysts, mining investors, professional advisers and the market operator. The balance of knowledge and understanding among these participants combined with the competition for capital, contributes to the standards for our mining market in a way that the market operator simply cannot replicate by market rules alone.

Jan 1, 2002

By Bulters J, Sheppard I

Two blasthole density logging programmes have been conducted on the Mt Whaleback iron ore mine to evaluate the use of this type of logging as an aid to blast pattern design. The first programme also involved the setting up of a Density Test facility with which to calibrate the density probe. The programmes indicated that about 22-23 blastholes can be consistently logged per day at a cost of $1.30 per metre. Even though this is only half the rate required to log the average number of blastholes drilled daily on Mt Whaleback, testwork indicated that no significant loss of accuracy results if only half the holes in a pattern are logged. The major results of the programmes were: 1. The density range for black pyritic Shale is 2.2-2,9 g/cc. 2. The density range for soft to medium hard BIF is 2.1-3.0 g/cc. 3. The density range for hard BIF is 3.0-3.6 g/cc. 4. The front row blastholes show consistently lower densities than the main body holes due to blast damage. 5. A low density zone extending to a maximum depth of 6 m occurs at the top of most blastholes and results from blast damage from the bench above. These density results have been used to implement savings in drilling and blasting via pattern expansion and charge optimisation of blastholes. Eight ore

Jan 1, 1986

Over the last thirty years production of heavy minerals from Australian deposits has dominated the world market. The main incentive has been to suoply the raw material for titanium dioxide based pigments. These ~ninerals include ilmenite, rutile, leticoxene and more recently, synthetic rutile. Inevitably the viabilit/ of developing placer type deposits has seen influenced by other heavy minerals present, such as zircon and monazite, but these have been of secondary importance. For most of the sixties and seventies, Australia supplied the 'najority of free world rutile and zircon, and a large proportion of the ilmenite. With the run-down of rutile- rich reserves in eastern Australia, the emphasis has s:iifted in several countries, including Australia, to fill }the gap with i l Wen i to and its derivatives, leucoxene, synthetic rutile and titanium rich slag. over the next 15 - 20 years, as high grade beach placers in Western Australia are mined out, less traditional sources for mineral sands products will be opened up. Low grade placers (particularly those dominated by ilmenite) will be reassessed in Australia, U.S.A., Africa and Asia, and exploration will shift from beach and dune environment, to heavy mineral concentrations in alluvials, lake deposits and continental shelf deposits. At the same time, production of anatase and bastnaesite will be expanded, as required, from the huge resources contained in carbonatites in 3razil, U.S.A. and China.

Jan 1, 1986

Every step on the path from the mine to the smelter invites a comparison between material inputs on one side and outputs plus accumulation on the other. Or put simply, between what you think you have produced with what you find you have at hand. The discrepancy between these sets of comparisons is the error. Following that error in a systematic and objective manner is a way to improve the mineÆs measurement systems, that in turn leads to more accurate accounting for ores, metals and concentrates. Because the control of production is so tightly coupled with the accounting of materials, any lasting improvements in materials accounting will benefit the predictions of materials movements and quality. This translates to more reliable planning and scheduling in stockpile management, logistics, shipping and marketing. The statistical tools described are direct adaptations from the long-standing methods used to maintain the quality of manufactured product in the discrete parts industries. Their use in the process industries, of which mining is one, requires some care owing to the continuous nature of ore extraction and its variable properties. The tools can be used for problem diagnostics and as early warning systems. In common practice many professional staff, in attempting to get a perfect reconciliation between expected and observed results, try to explain away the error or bury it completely. The methodology advocated here requires a different mindset because the error must be given pre-eminence for lasting improvement to be realised.

Jan 1, 2002

The basic principles of mineral valuation were recognised and propounded at the beginning of this century and have remained virtually unchanged since then. Valuation is seen as a two part process commencing with a technical examination of the mineral property followed by a manipulation of the results of the technical examination in order to determine the monetary value of the project. A thorough and competent technical examination was seen then and remains now as the essential but not sufficient foundation for reliable valuation. All authors stressed the need to maintain the integrity of the data base and to ensure adequate coverage of all relevant aspects. The monetary valuation process through most of the first half of this century was mainly based on the Hoskold two rate method, derived from the formulae for valuing annuities but modified to provide explicitly for recovery of capital. Though the basic principles of valuation have not changed significantly, the means of implementing the components of the technical examination, the styles of deposits being evaluated and the mechanisms of monetary valuation have changed dramatically. Despite all the technological improvements, however, mineral valuations are still as apt to vary from realised performance as at any time in the past. As well, mineral property valuations are now being extended to cover all assets of potential value, including valuation of exploration tenements with or without identified resources. Valuation of exploration tenements will continue to be one of the most difficult and contentious of valuation tasks.

Jan 1, 1994

THE treatment by chlorination of the Mount Morgan Gold Mining Company's ores was first accomplished, early in 1886, by a works having a capacity of 25,000 tons per annum. Shortly afterwards another works was established, capable of dealing with 50,000 tons per annum. The extraction of gold was originally successful and satisfactory, but running expenses were high, averaging £2 19s. 6d. per ton of ore treated. These works were believed to be the largest chlorination plants in the world at that time. As might have been expected, the mechanical details and chemical process had not been perfected, and, moreover, both works were hurriedly built, and operating expenses were not then considered of such prime importance, as the ore at that time was of very high grade; the large quantities of low grade ore since dealt with not being then considered, since the bulk of it was not even known to be in existence. These two works consisted of rock-breakers, high speed rolls, screens, elevators, &c., for crushing; a large number of small handrabbled reverberatory furnaces for roasting; one-ton chlorination barrels and three-ton leaching vats for chlorination. The transport of ore from crusher to furnaces, from furnaces to chlorination barrels, and the emptying of leaching vats was effected entirely by hand labour. The system of chlorination was what was, known as Mears process, chloride of lime and sulphuric acid being used in the chlorination barrels, and as the time allowed...

Jan 1, 1911

By Abraham B. K, Jensen B, Gillies A. D S

The aim of the research was to investigate the feasibility of using an impedance cell and ratio-transformer bridge to measure solids content in coal slurry pipelines. It appeared that this technique could be developed to measure variations in conductance which correlate with solids content. Successful implementation of the measurement technique would have a variety of applications in existing coal wash plants and the potential for automatic process control. A small pilot plant was designed for a feasibility study. This was a closed loop system in which the coal was uniformly dispersed in a tank with a variable speed agitator and then circulated through an external pipe returning to the top of the tank. The impedance cell was located near the end of the external pipe. Slurry concentrations were varied from clean tap water to 50 per cent solids by weight with the addition of weighed quantities of dry coal dust. Ratio-transformer bridge measurements showed that variations in individual observations were equivalent to measurement errors of about two per cent. These probably reflect variations in concentration of the mixture in the pipe. Data for increments in concentration of one per cent indicate that this is about the limit of resolution of the current system. The paper discusses the principles of operation of the impedance cell and measurement system. Results from the pilot study and proposed improvements in the impedance cell design are examined.

Jan 1, 1995

By K Gilliland

The past decade has seen the widespread implementation of computerised real-time operational management systems in open pit mines. While these systems have made a significant impact on operational efficiency at a process level, surprisingly little work has gone into integrating these systems with other IT systems, including those used for tactical planning and enterprise resource planning. As a result of this gap in the information hierarchy, the goal of optimising an entire operation, or multiple operations, remains elusive. Implementation of computerised operational management systems in underground mines has been much slower. This is a significant, though often overlooked, reason why the productivity for underground mining is generally so much lower than for open pits. The historical reluctance to implement computerised operational management systems underground can in part be attributed to the underground environment, particularly the difficulty in establishing effective communications. Another factor retarding the implementation of systems underground has been the perception that the nature and scale of underground mining does not lend itself to computerised operational management. This perception can be challenged, not only by a process level examination of the underground mining, but also by a holistic examination of the entire industry. In recent years, the mining industry as a whole has destroyed rather than created wealth and underground mines are major culprits. The degree of value destruct has been more pronounced with underground mines, as the usual problem û low commodity prices û has been exacerbated by the harsh environment, low productivity and a æfog of warÆ no longer generally found in open pits. Faced with these realities, underground mines will have to adopt modern management tools or suffer extinction at the hands of an unsympathetic investment community. All is not gloom and doom, however. Technological advances have largely overcome the difficulties associated with the underground environment. As a result, there is a small, but growing, number of underground mines using computerised operational management systems to directly improve the bottom line. Much greater improvements can be realised if the industry takes advantage of the recent convergence in technology, to integrate process information with tactical and enterprise resource planning systems in order to provide a solid platform for all decision-making. This would result in the æeÆ mine. Given that the underground fraternity is essentially starting with a blank sheet, they have the opportunity to æsteal a marchÆ on open pit mines, who may be constrained by legacy systems. The benefits of the æeÆ mine are presented through a hypothetical case study that examines the shortfalls of the non-æeÆ mine. The paper ends by presenting a future vision for the æeÆ mine.

Jan 1, 2000

The seemingly insatiable world demand for mineral and energy products is continuously pushing out the frontiers of exploration and development in countries around the Pacific Rim.

Jan 1, 1990