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I will confine my remarks to normal computers that people interact with, rather than built-in processors which exist in every watch and washing machine these days. I will also confine myself to computing in the technical side of mining. Bu

Jan 1, 1998

By S Nie, I Bergqvist, F Ouchterlony

In blasting, a few or many cracks are driven from the borehole into the rock. But what causes the cracks? The most common theory of breakage consists of two stages; first the shock wave causes radial cracks to form around the hole then the gases penetrate into the cracks, and widen them and make them longer. Another theory presented by Brinkmann suggests that the back damage is primarily controlled by shock and that the gas penetration is the mechanism controlling breakout of the burden. He did his experimental work using blasthole liners. Recent research at SveBeFo has examined this matter further. In a quarry a number of benching holes have been blasted simultaneously. In some of these holes tubular Swellex bolts were inflated and decoupled charges put inside the tubes without stemming. Other holes were identically charged but without the lining. Finally some holes were also stemmed. After blasting the cracks in the remaining rock were studied. There was no difference in crack lengths between holes charged normally (no stemming) and holes where the charges were inside the bolts. On the other hand when stemming was used, the crack lengths increased for some explosives but remained the same for an emulsion explosive. In another set up blasted granite blocks were charged in the same way as above. Then we could also measure the bore hole pressure. The pressure gauge consists of a small carbon resistor inside a steel cylinder. It is called LHM (Location-fixed Hydrodynamic Measuring Cup) and is placed at the bottom of the hole. A smaller exit hole from the bottom is drilled for the cables. The paper presents the technique and the results obtained from both the quarry blasting and the blasting of the blocks.

Jan 1, 2001

Recent developments in engine, transmission and control technology, likely to give rise to improved performance and efficiency of underground mobile equipment, are reviewed. Turbocharging and the electronic control of fuel pumps and injectors can improve diesel engine performance whilst minimizing exhaust emissions. Ceramic materials promise further improvements in engine efficiency. Nevertheless, electrically powered machines, equipped with trailing cables or 'travelling plugs' are expected to find increasing application where there is less need for flexibility and where the cost of ventilation and heating or cooling makes diesel engines unattractive. Voltage to frequency converters and induction motors appear to have a future in mains powered machines. Vehicles employing energy storage in the form of batteries or flywheels will find increasing application, but it is expected that they will remain a minority until there is a significant break-through in battery technology. Hydrostatic transmissions having high power density and efficiency are likely to be used more widely. Electronic control systems are likely to be used to simplify jobs and to improve performance and productivity. Enhancement of remote control systems is to be expected for work in unsafe areas, but true robot operation is considered unlikely for the moment. Attention to ergonomic factors should produce significant productivity gains.

Jan 1, 1985

Best practice in environmental performance is a principle now increasingly and rapidly transferred around the globe. This matches both the greater rigour of environmental standards and the growing uniformity and `internationalisation' of standards for environmental management. There is no difference in the application of Normandy's environmental policy anywhere in the world.Normandy Mining is developing an Environmental Management System (EMS) which will satisfy:ò the need for technical excellence and best practice;ò the need to demonstrate `due diligence' in any jurisdiction;ò the need for financial statements and for insurance to reflect real world requirements for management of risk and liability.

Jan 1, 1997

Changes in mining technology have led to an increase in the number of underground sulfide dust explosions reported in Australian and overseas mines. Samples collected at the Elura mine consisting primarily of pyrite, pyrrhotite, arsenopyrite, sphalerite and galena, were tested in 8 litre explosion chamber. The dusts were found to be capable of producing dangerous dust explosions with maximum explosion pressures of 440 kPa and rates of pressure rise of 5200 kPa/s. The hazards of a sulfide dust explosion are associated with the pressure wave and flame front of the explosion and the toxic gases remaining after the explosion.

Jan 1, 1984

By Muge F, Pereira H

In the early stages of the planning of a new exploitation, the error in ore reserve estimation is an important factor that must not be disregarded. As this error can be computed by geostatistical methods, the risk of the venture can be calculated for different recognition patterns in a certain assumption of economical conditions. A case story is described for an open pit phosphate deposit in which grade/tonnage curves and their confidence intervals are related to an economic function for three drilling patterns and decisions are taken on the basis of cost and value of supplementary information.

Jan 1, 1977

By Gadsden R. W

Physical and chemical requirements are defined for coke and ferrous materials used in modern high productivity blast furnaces operating in Australian conditions. Recent developments in the type of equipment required to be installed at the steelworks to ensure these requirements are described with illustrations from current plant practice provided.

Jan 1, 1976

Laboratory studies of batch and continuous screening of ferrous sinter mixtures (4-0.5 mm) are described. The results are analysed by an equation derived from the first-order rate law for the condition of decreasing screen residue.The results of the studies show that the two screening operations are comparable in all respects if deck length in continuous screening and time in batch screening are interchanged.It is shown that the general screening process is determined by the numerical values of the screening rate constants of each of the particle sizes in the feed mixture and that the relationship between these constants and the particle size/screen aperture ratios is related to the appropriate probability function of the same ratios.It is also shown that the screening rates decrease exponentially with the amount of near-mesh material present in the feed and that oversize particles can increase these screening rates for some screen motions and decrease them for others.

Jan 1, 1985

By Stitt P. H

This paper provides a brief historical review of the invention of the spiral separator and its adoption into Australian metallurgical practice. The purpose of the review is to demonstrate that spiral development to date appears to have been a largely empirical process, and that the cur- rent resurgence of interest in the spiral, especially in the coal industry, warrants an increased fundamental research effort. Current research work concentrating on empirical modelling is outlined, while some preliminary experimental results of a more fundamental nature are presented and some research of other disciplines interested in particle transport introduced in order to stimulate further work and discussion.

Jan 1, 1988

Western Mining Corporation (WMC), managers of the Windarra Nickel Project, installed a raise-bored haulage shaft and underground crushing system at the Mt Windarra Nickel Mine in 1982. The system is the second of its type installed by WMC, the first being at the Otter Juan Mine in Kambalda in 1976/77. Both haulage systems became necessary as a result of the increasing production limitations, and escalating costs of a deep decline mine.The Windarra haulage system required a single 3 m diameter vertical raise drill hole, 470 m deep and equipped for skip haulage. Two five tonne skips, in balance, hoist crushed ore and mullock to the surface, at a design rate of 200 tonne/hr, effectively reducing truck haulage leads by up to 50 per cent. The system is now fully operational and will enable the mine to achieve its maximum production rate.The raise-bored shaft system has been shown to be cost effective and would be used again in circumstances where raise drilling is applicable.

Jan 1, 1984

Truly launched during the 1939-45 war, b¬,osted since by huge increases in demand for food, shelter and manufactures of ill kinds, petrochemicals have rocketed into prominence' all'oVer''th'e world and are accelerating to even greater heights.Manipulation of the hydrocarbons in petroleum or natural gas provides raw materials for a wid.e'variety of plastics, resins, detergents, rubbers, chemical intermediates, fibres and fertilisers. These in. turn.. go into a host of products essential to our way of life.A5 a source of chemicals, petroleum has achieved a high place. because of its abundance, relative.eheapness acid ease "f transport and because it can,be' economically processed.'If a nation's industrial' progress is measured by ' the ' modern yardstick of petrochemical production,'Australia has reasonto be proud, for it now has 1S petrochemical plants worth'156 million, either in operation or under construction.At several locations near Sydney and Melbourne, these plants produce petroleum ethylene, propylene, butadiene and benzene, or convert these building blocks into the three major thermoplastics (polyethylene; polyvinylchloride and polystyrene)-a.nd"S.B.R.synthetic" rubber. "A number bf other imr-ortant petrochemicals, including carbon black, and ammonia, also are made, or-planned...Most petrochemicals find application. in seven principal industries - rubber, fibres, detergents, surface coatings, automotive, agriculture and plastics. They play a .part in many other industries, including mining and metallurgy.In Australia, population growth,.an -incr.easing standard of living, greater industrial activity and the replacement of older materials all should considerably expand the markets for established petrochemical plants and lead to the introduction of new manufactures.Unless thwarted, these positive forces should propel petro-chemicals into a future glittering with promise;' ò 'However, some help for the infant industry seems needed if petrochemicals, while growing with the nation, are to contribute as they can to our national development.

Jan 1, 1962

By Mould G. R

The paper presents a general background to the subsidence research programme being undertaken by the Department of Mineral Resources and Development in New South Wales. The results of the studies undertaken over the last ten years are summarised. The differences between these results and those obtained by the National Coal Board are discussed. The results of a study carried out on the effect of total extraction beneath a freeway in the southern coalfields are discussed in some detail. The procedures developed for the const- ruction of a 500 mm diameter natural gas pipe- line crossing a number of collieries in the northern coalfields are also outlined. The future direction of the Department's subsidence research programme is discussed.

Jan 1, 1980

By Haase W. C

The content of this paper will identify recent developments in walking dragline technology including utilisation of planetary swing dnves, high voltage generators, unique bucket configurations and increased machine capacity resulting from changes to front-end geometry. The benefits to mine operators for increased performance, reduced cost, improved availabilities, simplified maintenance, and ease of operation will be identified and discussed. The feasibility and application of the technology as a retrofit on existing equipment will also be covered in the presentation. All the technology being presented has been recently commissioned into operating Australian mining operations and will be presented from a practical, as well as theoretical perspective.When the Marion 8000-Series Dragline was introduced in the early-1970s, it quickly became the industry standard for high productivity and availability. Features like outboard bearing propel, four-chord deep section boom and the over/under fairlead have proven their superiority in thousands of hours of round-the-clock operations in a variety of tough digging conditions worldwide. Marion has currently sold 31 of these 8000-Series Draglines into the Australian mining community.

Jan 1, 1992

By R Lloyd

Coal Services (Health and Safety Trust) funded ARRB Transport Research Ltd to investigate fatigue and performance of truck drivers over consecutive shifts. The main questions were to assess: What is the most important contributor to acute fatigue in mining? Is it length of shift (eg eight hours versus 12 hours) or is it time of day (eg circadian effects)? What is the limit of successive day or night shifts before chronic fatigue affects operator performance in open cut mines? The project methodology included utilising ARRB Fatigue Monitoring Devices (forced-choice stimulus reaction) in eight haul trucks, testing 24 subjects over several weeks. Each subject filled in a Fatigue Risk Questionnaire on lifestyle and health. Operators worked a 14-night, one day off, 13-day roster of 12-hour shifts in a fly-in/fly-out operation with excellent opportunities for restorative sleep between shifts. A total of 3500 hours of real-time data was collected, representing the first set of objective, real-time driver performance data for Australian mining. The data showed that for a single night of driving haul trucks, there appears to be no effect on operator fatigue from the amount of time on task (for the 12 hours). In fact performance was worse through the first eight hours than the last four. The circadian influence had a stronger affect than working more than eight hours. Of the 14 nights worked at the site, nights 13, 14, seven and two respectively, were the worst. This presents a conundrum for policy makers who may like to place caps on working hours or rosters in the hope that it will alleviate the fatigue issue. It will not. The major finding within this study is the combined influence of circadian rhythms (human body clock) and individual variability on performance. The lifestyle habits and the health of individuals have a profound effect on operator performance as shown by the strong positive correlation between high fatigue risk scores from the Fatigue Risk Questionnaire and poor performance. An individualistic approach would appear to have the best chance of reducing high potential incidents due to fatigue through successive nightshifts.

Jan 1, 2005

By Leigh G, Gottleb G, Wilkie G

The estimation of particle liberation is important in the study of mineral concentration. With simple systems, where the densities of the components are low, the liberation can be studied directly by density fractionation. For most practical systems, and particularly for the dense, complex sulphides, the only method known is by measurement in polished section. There are two major difficulties with such measurements. Firstly, the measurements themselves are difficult and considerable care is needed before reproducible results can be achieved. Secondly, a well known stereological problem arises which gives the estimates an inherent bias. The paper discusses both aspects of the problem. The practical features of measurement are treated in detail and a method described which has been developed and proven to give reproducible estimates of the liberation in the section. This discussion relates to automated measurements by QEM*SEM and presents a way of estimating the confidence limits within which measurements lie. Comparisons are shown between measurements made by the traditional manual optical technique and automated equipment. Stereological reconstruction is also discussed briefly. Several methods have been presented in the literature but all are complex and none is yet widely accepted. Area measurements are less biased than linear estimates so a practical approach is to use area measurements in uncorrected form. The topic is still being actively researched so it is expected that one method will soon emerge as the standard technique.

Jan 1, 1993

By Whitmore R. L

The action of water on a number of Queensland shales which are associated with particular coal measures and oil shales has been studied. The results suggest that the disintegration of some of the shales could cause significant problems in mining and preparation operations. The extent of shale breakdown varies widely from deposit to deposit and from seam to seam but a suitable assessment procedure utilises the test described in AS 1661-1979, and an improved method of presenting the results is described in the paper.

Jan 1, 1982

Groundwater issues for the mining industry are many and varied. When the depth of mining is below the water table/potentiometric surface, a groundwater æsinkÆ is created which alters the local groundwater flow regime resulting in minewater inflows. Assessment of mine dewatering, mine water balance and wastewater disposal requirements are central to the effective management of water in a mining operation. Each of these issues has a significant groundwater component. Other groundwater issues for mining operations include: water supply, aquifer storage and recovery, the impact on other groundwater users in respect of groundwater levels, bore yields and water quality, and the development of an effective groundwater monitoring network for early detection of impacts and to satisfy regulatory requirements. This paper outlines the techniques involved in assessing groundwater issues for project feasibility, during operation and post closure, and provides an overview of several mine dewatering and water disposal methods. The practical assessment of groundwater issues for the mining industry is illustrated with several case studies of mining projects in Australia, SE Asia and the subcontinent. These are projects to which the author has contributed during a career as a geologist/hydrogeologist spanning more than 25 years.

Jan 1, 2003

The optimisation of capital in the total planning context has broadly two components: ò maximising the efficient utilisation of capital against competing capital demands; and ò maximising the efficiency with which the industry's capital requirements are sourced. This paper focuses on the latter of these two concepts, as I wish to highlight that within the coal industry the inefficient sourcing of capital has resulted in the inefficient utilisation of capital. In discussing the optimisation of capital within the coal industry I would like to outline three fundamental issues which currently impact the industry and its application of capital: Initially, from the perspective of an independent investor, the perceived risk associated with investing in a volatile industry cycle has not permitted appropriate funding structures to be created thus leading to an inefficient utilisation of capital. Secondly, investors seeking out a windfall gain have established a practice of trading in the assets rather than encouraging recapitalisation. And lastly the mismatch of supply and demand leading to the establishment of new projects which include a percentage of offshore investment has fostered an environment of lower returns and subsequently a dilution of capital.

Jan 1, 1991

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

The quantity, quality and detail of project information increases as project development moves from initial scoping level studies, to pre-feasibility and option studies, then definitive feasibility study and basic engineering stages. Data accumulates from metallurgical and vendor testing from various ore types and composites carried out to assess physical characteristics and processing responses of the ore. Over-simplification or assumptions about the orebody for flow sheet development can result in using æaverageÆ information for design. Use of averages of data can have adverse implications on sizing of plant and equipment and consequently on definitive study cost estimates and detailed engineering. In practice, the treatment plant workforce is faced with managing a non-homogeneous or non-average orebody in a variable operating environment that is not always predictable. This paper presents views on how to use the data generated from testwork in project development and for process and plant design. Examples of process design risk or operating risk are presented. Although this topic is applicable to the broad range of process design decision making in the minerals industry, this discussion references comminution, flotation and extraction processes for gold and base metal ores.

Jan 1, 2004