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Most of you who are attending this conference are probably Student Members of The Institute and well aware of the advantages which flow from student membership. You will probably agree that the major benefits are: ò Low and subsidised membership fees;

Jan 1, 1994

The first steps towards the use of artificial intelligence to manage ground conditions have been made. Millar and Hudson (1993) outline the theory behind the use of neural networks in monitoring rock engineering performance.

Jan 1, 1994

By Yambu J, Titus K

Geotechnical investictations and monitoring have been integral to development of the Porgera Gold Mine. The steep, unstable terrain has required a program for monitoring of slopes and foundations which includes survey stations, borehole inclinometers and piezometers. Case studies of the Maip Pass landslide, Yakatabari land-slide, Anawe Plant Site CIP pond excavation and batter, and a load test study for mine waste dumps are presented.Monitoring is needed to ensure that geotechnical risk is kept to a minimum. A vigilant program will be required for the life of the mine.

Jan 1, 1994

The deep seafloor in Papua New Guinea's proposed Exclusive Economic Zone appears to be a gold-rich province in the same sense as the territory above sea level. Two significant sites with polymetallic massive sulphide deposits forming today are known on neovolcanic ridges in the Manus Basin. Their high precious metal contents have led to renewed interest in the issue of exploiting seafloor mineral deposits. The prospects of finding other, possibly larger deposits in the region appear substantial. This paper reviews current data on seafloor deposits in Papua New Guinea (PNG) and raises some issues relating to future commercial exploration and mining of the sea floor. One of the known PNG deposits could become a prime candidate for the trials needed to develop technology, establish costs, and minimise environmental impact.

Jan 1, 1994

By Thompson M

The humble gabion basket is to mine development what the light bulb and safety pin are to eir-ryday life. Gabions provide a flexible, easy to assemble and cost efficient solution for "101" mine and civil engineering development applications.In some instances gabion baskets are still efficiently in use after many years of faithful, maintenance-free service. In other situations, the baskets have been demolished or made redundant within days, either having served their temporary usefulness or negligently destroyed by the operator of heavy equipment. Either way, the gabion basket must surely rate among the top 10 cost efficient engineering construction materials.

Jan 1, 1994

By Smith I, Gowan M

With the advent of increased environmental regulation and high penalties for non-compliance in many countries, there has grown a need for all industries to assess their risk with respect to environmental compliance and consequently develop management systems which ensure environmental compliance and sound environmental practice. The need to better assess and manage environmental risk has developed rapidly as legal and financial penalties have increased for inappropriate management of the environment. The mechanism that industry has developed to manage risk is through the use of environmental management systems. These environmental management systems are generally based on the principles of total quality management. For example the British Standard BS7750 (Specification for Environmental Management System) shares common management system principles with ISO 9000 quality management systems. The same trends of increased environmental regulation and higher penalties for environmental impairment are now evident in Australia where environmental management systems are now being introduced. With increased penalties for environmental impairment and greater responsibility of managers and directors, environmental management systems are likely to become even more common in Australia. This paper describes some of the influences directing environmental management within the Australian industrial and mining environment, describes the elements of an environmental management system and relates these to the mining industry.

Jan 1, 1994

In line with DML Resources continual forward management policies, the Roscommon Quarry operation has recently installed and commissioned a Nordberg 7 ft Symons cone crusher and a HP 300 cone crusher. Both machines have enhanced the production capabilities and quality control of the Roscommon comminuition circuit and they will provide efficient and reliable crushing well into the next century.

Jan 1, 1994

Metsim is proving to be a powerful tool when designing a heap leach operation. The most useful outputs arc determining the fluctuations in pregnant solution recovery rate, make-up water rate, gold recovery rate. and pond levels. Detailed data are needed for input: a pad loading schedule, a mining rate schedule for each ore type, column leach test data for each ore type, column tests on water dynamics (ie hourly flow-out versus-in during saturation and drain-down), monthly rainfall and evaporation data, and proposed pond dimensions. These data allow 'what if' studies on application rates, leach rates, loading rates and other variables of interest. Examples will he given of modelling both a rectangular pad and a valley fill operation.

Jan 1, 1994

The ""comparable sales"" method of valuation attributes value to an asset by reference to actual sales of comparable assets or to the market capitalisation of companies with comparable assets. This methodology is widely used in real estate valuations. The real estate approach can be used to value mining and exploration properties where there are actual sales of comparable or similar assets in the recent past. The practical limitations of the comparable sales method are well known and self evident: limited number of transactions, limitations on comparability and inadequate data. The real value of the comparable sales method is in its use as a validity check. Estimates of value of mining and exploration assets are so sensitive to so many variables that all valuation methods have limitations. Accordingly there is real value in attempting to establish benchmarks from comparable sales. Apparently sophisticated valuation methods can mislead by creating the impression that valuation is a precise science. The judgement of the valuer is critical and judgements can be wrong. Any available evidence from actual sales that are even remotely comparable can provide useful input to the valuation process.

Jan 1, 1994

By Shrivastava P, Humphreys M, Guibal D, Deraisme J

Customer requirements concerning the final products of iron mines are extremely stringent. Because of this, there is an ever-increasing need for mine operators to monitor and strictly control the quality of their product. This quality, as measured by the stockpile grade variability, is the result of a very complex process, where natural characteristics (the orebody and its geology) are transformed through the mining technique (open pit, shovel and truck fleet, blending into stockpile). The only way to reproduce and hence to control the variability of such a system, which is composed of several interactive sub-processes, is by simulation. A complete simulation of a Hamersley Iron Pty Ltd (HI) ore deposit has been undertaken to forecast the impact and cost of various mining methods, mining schedules and product stockpile sizes on variability of chemical and physical characteristics of the products. The mining simulation was made on a conditionally simulated orebody. On a range of criteria, the simulation was considered to fulfil the objectives set and was a valuable aid to analysis of product grade variability, operating and capital costs, selection of equipment, mine scheduling and setting of product grade targets.

Jan 1, 1994

The offshore Maui gas/condensate field was discovered by Shell BP and Todd on Services Limited in 1969. Subsequent appraisal drilling and negotiations with the Government led to a development agreement, æThe Maui White Paper' being concluded in 1973. Part of this agreement provided for the Government to take a 50 per cent shareholding in the field. The field is comprised of a double domed anticlinal structure containing two gas reservoirs at depths ranging from 2700 - 3000 m. Water depth is 110 m. The development plan called for two standalone steel platforms to be installed sequentially over a period of some years depending on gas demand. The first platform (MPA) was put in place in 1976 but difficulties were experienced with piling and drilling of the 12 (later increased to 14) wells did not start until 1978. First gas was piped ashore late in 1979.

Jan 1, 1994

The Ok Tedi open pit mine will have final wall heights in excess of 750m. The behaviour of these excavated slopes will be influenced by the presence of numerous defects. This paper discusses the identification of possible failure mechanisms within the pit walls based on mapped fault and joint data. Results from analyses using these data have formed the basis for the ultimate pit design.

Jan 1, 1994

One common public perception of mining is that financially it is an extraordinarily risky business. Another and contrary view, in certain circles, is that price risk and other financial risks can be relatively easily removed or shifted by a number of schemes or devices. In reality, beyond the orebody discovery stage, mining need not be any more risky than most heavy industrial businesses. Nevertheless, as stated by Rappaport, (1986): Risk is a parameter of central importance in establishing the economic value of any asset. The level of risk is determined both by the nature of the firm's operations and by the relative proportions of debt and equity used to finance its investments. These two types of risk are commonly referred to as 'business risk' and 'financial risk' respectively. The term financial risk is used somewhat more loosely herein to recognise the reality that any risk inadequately addressed in the design, construction and operation of a mining project can have significant financial consequences; usually negative. For instance, a specific area of business risk in mining is often called technical risk which definitely has severe financial consequences if not managed correctly. The various risk shifting, hedging and risk management tools available all have their place and range from merely useful to almost indispensable. However, in the long-term, financial risks are maintained at acceptable levels by the application of sound, more fundamental business management principles. There are many with a vested interest in perpetuating a perception that the conceptual foundations of sound management practice are extremely complex. In reality, most management concepts are prosaic, but their application requires incredible discipline and hard work. There is no magic formula or 'silver bullet'. It appears that a company whose activities are restricted to mining can analyse the range of risks specific to mine development and operations more clearly than companies in which mining is just one of many businesses. The almost universal failure of large oil companies in the mining business is probably the best example of lack of any clear comprehension of fundamental business characteristics and risks. Conversely, in regard to risk management, choosing to be in other business as well as mining does nothing to reduce the risks of the mining business. The individual shareholder can probably make such 'diversification of portfolio' decisions better than most management teams. It could be argued that diversification across a number of disparate businesses may actually increase overall corporate risk due to lack of management concentration and focus. These differences between the perceptions of financial risks and the realities in mining need to be further elaborated in relation to some uncompromising business concepts.

Jan 1, 1994

By Porter I

Rock mass classification systems have emerged as a powerful tool which can be used for assessing ground conditions and determining support requirements in underground mines. They should not be used as a substitute for complete engineering design, but rather as a supplement to observational methods and analytical study. In general, the use of rock mass classification is attractive, but each classification system has various deficiencies. Use of any particular system should be made only with knowledge of that systems limitations. It is desirable to employ a number of systems and design methods which will allow for comparison and lead to a better understanding of the rock mass condition.The Rock Mass Quality system (Q-System), developed by the Norwegian Geotechnical Institute, and the Rock Mass Rating (RMR) System, Bieniawski, were designed primarily for civil engineering structures. Laubscher et al (1978) further developed the RMR-system specifically for rock mechanics engineering in the mining industry. A method of stope design, which introduces a stability factor for the rock mass and compares this with hydraulic radius, was developed by Mathews et al (1981). This paper reviews the above systems by applying them to stability assessment of crown pillars in two Australian metal mines and provides a critical analysis of the various approaches. In particular each system will be analysed to determine its suitability for use in crown pillar design. The most suitable system(s) will form the basis for future development in crown pillar stability analysis.

Jan 1, 1994

The Mt Leyshon Gold Mine is located 30 kilometres south of Charters Towers in Northern Queensland. The current open cut mine has been in operation since 1986. In 1992 a feasibility study was completed that recommended an increase in production to over 240 000 ounces of gold per year. This proposal required an upgrade of the processing plant to five million tonnes per year, and an enlarged mining fleet to provide additional ore, and to meet the increased waste removal requirements. The implementation of the mine expansion program during 1993 required the Life of Mine plan to be extensively revised. This required the assessment and management of potential risks associated with the mine design. The updated geological model using the 1992 drilling results along with the actual contract mining and processing costs were used to establish a series of nested optimised pit shells. The total and incremental quantities and costs were then analysed to determine a suitable pit perimeter. The pit and phase plans were then created and used to devise a staged development plan. The block layout plans for each bench were then established from which a detailed life of mine production schedule was created.

Jan 1, 1994

Gold mineralisation was first noted in 1983 at the Wapolu Point area of Fergusson Island, Papua New Guinea (PNG) during a follow-up regional reconnaissance program. Subsequent exploration programs through to late 1987 completed 22,147m of costean trench sampling, 553 aircore/RC/diamond core drill holes (16,970.5m total) and metallurgical testwork, predominantly on the Wapolu grid in two mineralised areas.Subsequently in 1988, geostat-istical global and polygonal resources were calculated for the main mineral-ised zones, Didigayagaya and Dagwalala. In 1992, a 'probable total reserve' of 1.9Mf @ 2.4g/t with a 1.2g/t cut-off was calculated for these prospects.

Jan 1, 1994

There is a well-known saying, variously attributed to the great King Solomon and other sages of antiquity, to the effect that 'there is nothing new under the sun'. The inventive genius of man, as far as it is personified in the metallurgist, has often had the truth of this statement poignantly brought to mind when investigating the priority of ideas in its own particular branch of science. Not infrequently some operation, at first inilocently taken for a novel procedure, has later been found to have had an irrefutable precedent in the more or less remote past.When confronted by a question of this kind the metallurgist can generally much simplify his search if he at once turns his scrutinising gaze towards that ancient home of metallurgy, Germany. Vast departments of the smelting art have originated there, and even when Germany has not been in position to claim priority of invention, it has at least been characterised by a distinction equally as worthy - ie that of the faithful and authoritative exposition of the theoretical grounds on which the invention rests.In the present instance, in endeavouring to trace the history of pyritic smelting, the writer has naturally turned in the abovementioned direction, and not without some result, although the recorded data are, as might have been expected, meagre. A complete history of the art of beneflciating ores by means of fire, in all its many ramifications, still remains to be written. Possibly it may never be written, for the extent of the subject is tremendous. It is even practically impossible to clearly trace the development of one of its most modest sub-branches in satisfactory detail, or to present that branch without going to a considerable extent into related matters of a merely general character. For the purpose of dealing with the subject it will be convenient to divide it into two concurrent heads, and to distinguish, for historical reasons as well as for metallurgical ones, between that branch of the general method of matte smelting, which, until about 1891, has been called 'pyritic smelting', and the more recent offshoot of the latter, which, by distinction, may be called 'pyrite smelting'. The nature of pyritic smelting was clearly defmed by Dr John Percy in 1880, and his interpretation3 may be accepted as well known. To recall the characteristics of the method we may perhaps paraphrase Dr Percy's meaning by describing the process as a special method for the smelting of lean or dry silver or gold ores, which do not contain sufficient lead or copper for these metals to act conveniently as collectors of the precious metals. The operation is conducted in a blast furnace, with an amount of carbonaceous fuel sufficing to produce an exclusively reducing atmosphere, and with the addition of pyrites, in order to form a regulus in which the precious metals shall be concentrated, the pyrites themselves being either argentiferous, auriferous, or cupriferous, or any combination of these three, or wholly barren of metal values. In the common acceptation of the term, it is understood that the use of the reverberatory furnace is excluded.

Jan 1, 1994

By Bucknell WR, Clarke DE

The paper provides a company's view of the relative merits of various valuation methods and outlines the basic approach it takes to the valuation of an exploration property. The negotiating process and methods of acquiring an interest in an exploration property is discussed The valuation methods discussed are: 1. Exploration Expenditure. 2. Real Estate. 3. Joint Venture Terms. 4. Rule of Thumb. 5. Net Present Value - Discounted Cash Flow. 6. Geoengineering.

Jan 1, 1994

By Lindbeck K

The mining industry in Western Australia is a large sector of the WA economy providing $12 billion (1993) of the export income for the State. Historically, mining in WA developed from traditional prospecting in the late-1880s leading to major underground operations by the turn of the century. Large open pits were developed in WA following World War II and became increasingly common since the gold boom of the 1980s. With the development of the open pits has been concomitant evolution of mining legislation, principally the Mining Acts of 1904 and 1978, which has been also accompanied by a practical evolution of the administrative system within the Department of Minerals and Energy. The mining industry has recognised the need for sound environmental management at mine sites, taking up the challenge and becoming a world leader in rehabilitation techniques. Any environmental management program in the industry has three stages: approval by government; management by the industry; and return to the State in an environmentally acceptable condition. The WA environmental requirements, procedures and industry performance in these three stages are discussed.

Jan 1, 1994

Thank you for asking me to address you. The topic may sound formidable. Those of you with determination to go somewhere in your careers will understand that by taking geoscience, mining and metallurgy courses as students, you are declaring your intere

Jan 1, 1994